Information on EC 2.3.1.169 - CO-methylating acetyl-CoA synthase

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The enzyme appears in viruses and cellular organisms

EC NUMBER
COMMENTARY
2.3.1.169
-
RECOMMENDED NAME
GeneOntology No.
CO-methylating acetyl-CoA synthase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
pathway; the corronoid protein functions as methyl group carrier during acetyl-CoA synthesis and decomposition
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
Enzyme accepts the methyl group from the methylated corrinoid/iron-sulfur protein, binds a carbonyl group from CO, CO2, or the carboxyl of pyruvate, and binds coenzyme A. Then the enzyme catalyses the synthesis of acetyl-CoA from these enzyme bound groups. Additionally the enzyme catalyses two exchange reactions between the methylated corrinoid/iron-sulfur protein and methylated enzyme and between methylated enzyme and the methyl moiety of acetyl-CoA.; pathway; the enzyme-bound complex is an [NiFe3-4S4]-acetyl complex
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
enzyme contains binding sites for the methyl, carbonyl, and CoA moieties of acetyl-CoA and catalyses the assembly of acetyl-CoA from these enzyme-bound groups, under optimal conditions the rate-limiting step involves methylation of enzyme by the methylated corrinoid/iron-sulfur protein; pathway
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
Enzyme accepts the methyl group from the methylated corrinoid/iron-sulfur protein, binds a carbonyl group from CO, CO2, or the carboxyl of pyruvate, and binds coenzyme A. Then the enzyme catalyses the synthesis of acetyl-CoA from these enzyme bound groups. Additionally the enzyme catalyses two exchange reactions between the methylated corrinoid/iron-sulfur protein and methylated enzyme and between methylated enzyme and the methyl moiety of acetyl-CoA.; pathway
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
the multienzyme complex contains at least two protein components: a CO-oxidizing Ni/Fe-S component and a Co/Fe-S component
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
pathway
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
the FeS cluster is present to relay electrons from enzyme to CO; the transfer of methyl group to enzyme occurs by SN2-type nucleophilic displacement, not a radical, reaction
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
kinetics of methyl group transfer between the cobalt of the corrinoid/iron-sulfur protein and the nickel of Ni-X-Fe4S4 cluster, called the A-cluster of enzyme, the reaction is reversible; pathway
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
pathway; the Ni-Fe4S4-5C cluster of enzyme catalyses the reversible reduction of CO2 to CO and is located in the beta-subunit. CO generated at this site migrates through the tunnel to the A-cluster, located in the alpha-subunit, where it reacts with CoA and a methyl group to generate acetyl-CoA. During catalysis, the two sites are mechanistically coupled.
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
The transfer of Co bound methyl group from methylated corrinoid/iron-sulfur protein to acetyl-CoA synthase is an SN2 attack of a nucleophilic center of enzyme, presumably Ni4, on the methyl-Co(III) stat of the corrinoid/iron-sulfur protein, generating Co(I) and methylating acetyl-CoA synthase.
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
two electrons are required for reductive activation of enzyme, starting from the oxidized state containing Ni2+. A Ni0 state may form upon reductive activation and reform after each catalytic cycle
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
investigation of putative intermediate states from the catalytic cycle by hybrid density functional theory. A mononuclear mechanism in which CO and CH3 bind the proximal nickel is favored over the binuclear mechanism in which CO and CH3 bind the proximal and distal nickel ions resp. The formation of a disulfide bond in the active site could provide the two electrons necessary for the reaction if methylation occurs simultaneously. The crystallographic closed form of the active site needs to open to accomodate ligands in the equatorial state
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
stopped-flow analysis of two steps within the catalytic cycle. Vast majority of enzymes within a population should be in the methylated form suggesting that the following CO insertion step is rate limiting. Reaction rate is most sensitively affected by a change in the rate coefficient associated with the CO insertion step
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
CoA is the last substrate to bind and CO and the methyl group bind randomly as the first substrate in acetyl-CoA synthesis
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
CO migrates to the A-cluster through two pathways, one involving and one not involving the tunnel
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
the methyl and carbonyl groups bind to ACS in a random manner before the strictly ordered binding of the third substrate, CoA, mechanism of acetyl-CoA synthesis by ACS, overview
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
chemical steps and conformational changes in the mechanism of acetyl-CoA synthase, overview
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
chemical steps and conformational changes in the mechanism of acetyl-CoA synthase, overview
Carboxydothermus hydrogenoformans DSM 6008, Methanosarcina thermophila TM-1
-
-
acetyl-CoA + corrinoid protein = CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
REACTION TYPE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
demethylation
-
-
-
-
PATHWAY
KEGG Link
MetaCyc Link
Carbon fixation pathways in prokaryotes
-
methanogenesis from acetate
-
Microbial metabolism in diverse environments
-
reductive acetyl coenzyme A pathway
-
SYSTEMATIC NAME
IUBMB Comments
acetyl-CoA:corrinoid protein O-acetyltransferase
Contains nickel, copper and iron-sulfur clusters. Also catalyses exchange reactions of carbon between C-1 of acetyl-CoA and CO, and between C-2 of acetyl-CoA and methyl corrinoid protein. Involved, together with EC 1.2.7.4, carbon-monoxide dehydrogenase (ferredoxin), in the synthesis of acetyl-CoA from CO2 and H2. To follow its stoichiometry, the reaction can be written as: CH3-CO-S-CoA + protein Co+ + H+ = CO + protein Co2+-CH3 + HS-CoA.
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
ACDS multienzyme complex
-
-
ACDS multienzyme complex
-
-
-
acetyl-CoA decarbonylase/synthase multienzyme complex
-
-
acetyl-CoA decarbonylase/synthase multienzyme complex
-
-
-
acetyl-CoA decarboxylase/synthase
-
-
-
-
Acetyl-CoA synthase
-
-
-
-
Acetyl-coenzyme A synthase
-
-
-
-
acetyl-coenzyme A synthase/carbon monoxide dehydrogenase
-
-
Carbon monoxide dehydrogenase
-
-
-
-
carbon monoxide dehydrogenase-corrinoid enzyme complex
-
-
-
-
carbon monoxide dehydrogenase/acetyl coenzyme A synthase
-
-
carbon monoxide dehydrogenase/acetyl-CoA synthase
-
-
-
-
carbon monoxide dehydrogenase/acetyl-CoA synthase
P27989
-
carbon monoxide dehydrogenase/acetyl-coenzyme A synthase
P27989
-
CO dehydrogenase
-
-
-
-
CO dehydrogenase enzyme complex
-
-
-
-
CO dehydrogenase/acetyl CoA synthase
-
-
CO dehydrogenase/acetyl coenzyme A synthase
-
-
CO dehydrogenase/acetyl-CoA synthase
-
-
CO dehydrogenase/acetyl-CoA synthase
Carboxydothermus hydrogenoformans DSM 6008
-
-
-
CODH
-
-
-
-
CODH/ACS
Carboxydothermus hydrogenoformans DSM 6008
-
-
-
CODH/ACS
P27989
-
CODH/ASC
-
-
-
-
multienzyme carbon monoxide dehydrogenase complex
-
-
-
-
multienzyme CO dehydrogenase/acetyl-CoA synthase complex
-
-
-
-
CAS REGISTRY NUMBER
COMMENTARY
176591-19-8
-
64972-88-9
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
Carboxydothermus hydrogenoformans DSM 6008
gene acsB
-
-
Manually annotated by BRENDA team
two CODH/ACS isozymes Cdh1 and Cdh2
-
-
Manually annotated by BRENDA team
Methanosarcina thermophila TM1
TM1
Uniprot
Manually annotated by BRENDA team
bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase
-
-
Manually annotated by BRENDA team
formerly Clostridium thermoaceticum
UniProt
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
evolution
-
comparison of bifunctional CO dehydrogenase/acetyl-CoA synthase enzyme from anaerobic bacteria and of the acetyl-CoA decarbonylase/synthase (ACDS) multienzyme complex from Archaea, and of the role of the ACS N-terminal domain in promoting acetyl C-C bond fragmentation at the A cluster, overview
evolution
Carboxydothermus hydrogenoformans DSM 6008, Methanosarcina thermophila TM-1
-
comparison of bifunctional CO dehydrogenase/acetyl-CoA synthase enzyme from anaerobic bacteria and of the acetyl-CoA decarbonylase/synthase (ACDS) multienzyme complex from Archaea, and of the role of the ACS N-terminal domain in promoting acetyl C-C bond fragmentation at the A cluster, overview
-
malfunction
-
in the ACSChDLETAN truncation mutant, the Km value is decreased to about one-seventh of its value in the full-length protein, and the Vmax value is increased by a factor of around 4.4. Overall, the Vmax/Km ratio increases by around 30fold, indicating an apparent unmasking of the intrinsic catalytic efficiency for overall synthesis of acetyl-CoA. Changes in the kinetics of acetyl-CoA synthesis are possibly due to differences in CO accessibility to the A cluster in different forms of the enzyme
malfunction
Carboxydothermus hydrogenoformans DSM 6008
-
in the ACSChDLETAN truncation mutant, the Km value is decreased to about one-seventh of its value in the full-length protein, and the Vmax value is increased by a factor of around 4.4. Overall, the Vmax/Km ratio increases by around 30fold, indicating an apparent unmasking of the intrinsic catalytic efficiency for overall synthesis of acetyl-CoA. Changes in the kinetics of acetyl-CoA synthesis are possibly due to differences in CO accessibility to the A cluster in different forms of the enzyme
-
physiological function
P27989
CODH/ACS is used in the degradation of acetyl-CoA to form methane and CO2
physiological function
-
acetyl-CoA synthase, ACS, a subunit of the bifunctional CO dehydrogenase/acetyl-CoA synthase, CODH/ACS, complex of Moorella thermoacetica requires reductive activation in order to catalyze acetyl-CoA synthesis and related partial reactions, including the CO/acetyl-CoA exchange reaction
physiological function
-
the five-subunit archaeal CO dehydrogenase/acetyl CoA synthase multienzyme complex, catalyzing both CO oxidation/CO2 reduction and cleavage/synthesis of acetyl-CoA, is an important enzyme for this process as well as for methanogenic growth on carbon monoxide. Isozyme Cdh1 contributes significantly to overall CODH activity in Methanosarcina acetivorans
physiological function
-
direct synthesis and cleavage of acetyl-CoA are carried out by the bifunctional CO dehydrogenase/acetyl-CoA synthase enzyme in anaerobic bacteria
physiological function
-
direct synthesis and cleavage of acetyl-CoA are carried out by the acetyl-CoA decarbonylase/synthase, ACDS, multienzyme complex in Archaea
physiological function
-
CODH/ACS is the only protein required to catalyze exchange of the carbonyl group of acetyl-CoA with free CO. CODH/ACS acts on both the acetyl C-C and C-S bonds in acetyl-CoA, and it identified CODH/ACS as the condensing enzyme that catalyzes the final steps in acetyl-CoA synthesis in acetogenic bacteria
physiological function
Carboxydothermus hydrogenoformans DSM 6008
-
direct synthesis and cleavage of acetyl-CoA are carried out by the bifunctional CO dehydrogenase/acetyl-CoA synthase enzyme in anaerobic bacteria
-
physiological function
-
direct synthesis and cleavage of acetyl-CoA are carried out by the acetyl-CoA decarbonylase/synthase, ACDS, multienzyme complex in Archaea
-
metabolism
-
expression of the Cdh1- and Cdh2-encoding genes is regulated differentially in response to growth phase and to changing substrate conditions. CdhA3 clearly affects expression of cdh1, suggesting that it functions in signal perception and transduction rather than in catabolism
additional information
P27989
bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase, the different active sites of this bifunctional enzyme complex are connected via a channel, 138 angstroms long, that provides a conduit for carbon monoxide generated at the C-cluster on one subunit to be incorporated into acetyl-CoA at the A-cluster on the other subunit. The enzyme catalyzes two different reactions. The C-cluster in the CODH subunit generates CO from CO2, while the A-cluster of the ACS subunit combines the CO with CoA and a methyl group to form acetyl-CoA
additional information
-
open and closed conformations of ACS, overview
additional information
-
open and closed conformations of ACS, overview
-
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
?
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
r
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
r
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
Fd-II can act as a redox mediator by accepting electrons from the acetyl-ACS intermediate and by serving as the initial reducing agent linked to formation of the Ni1+-CO catalytic intermediate
-
-
?
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
Methanosarcina thermophila TM-1, Carboxydothermus hydrogenoformans DSM 6008
-
-
-
-
r
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
show the reaction diagram
-
-
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
show the reaction diagram
-
under anaerobic conditions
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
show the reaction diagram
-
under anaerobic conditions
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
show the reaction diagram
-
under anaerobic conditions
-
-
?
CH3-CO-S-CoA + H+ + tetrahydromethanopterin
CH3-tetrahydromethanopterin + CO + HS-CoA
show the reaction diagram
P72021
-
-
?
CH3-CO-S-CoA + tetrahydrosarcinapterin + H2O
CH3-tetrahydrosarcinapterin + CO2 + H+ + electron
show the reaction diagram
-
the carbon monoxide dehydrogenase-corrinoid enzyme complex catalyzes the cleavage of acetyl-CoA, tetrahydrosarcinapterin functions as the methyl group acceptor, the major products of reaction are methyltetrahydrosarcinapterin and CO2, free CoA is identified as an additional product
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-
-
CH3-CO-S-CoA + tetrahydrosarcinapterin + H2O
CH3-tetrahydrosarcinapterin + CO2 + H+ + electron
show the reaction diagram
-
the carbon monoxide dehydrogenase-corrinoid enzyme complex catalyzes the cleavage of acetyl-CoA, tetrahydrosarcinapterin functions as the methyl group acceptor, the major products of reaction are methyltetrahydrosarcinapterin and CO2, free CoA is identified as an additional product
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
show the reaction diagram
-
-
-
-
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
show the reaction diagram
-
-
-
-
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
show the reaction diagram
-
-
-
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
show the reaction diagram
-
this multistep reaction involves four proteins: CO dehydrogenase, methyltransferase, the corrinoid/iron-sulfur protein and ferredoxin
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
show the reaction diagram
-
The methyltransferase catalyses the reaction of CH3-H4folate with the corrinoid/iron-sulfur protein to form a methylcobalt species. The Ni/Fe-S enzyme CO dehydrogease then catalyses the final steps in the formation of acetyl-CoA.
-
?
CH3-tetrahydrosarcinapterin + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrosarcinapterin
show the reaction diagram
-
-
-
?
CH3I + CO + HS-CoA
CH3-CO-S-CoA + HI
show the reaction diagram
-
-
-
?
CH3I + CO + HS-CoA
CH3-CO-S-CoA + HI
show the reaction diagram
-
-
-
?
CH3I + CO + HS-CoA
CH3-CO-S-CoA + HI
show the reaction diagram
-
the multienzyme complex catalyses the acetyl-CoA synthesis from CH3I, CO and CoA as well as to cleave acetyl-CoA into its methyl, carbonyl, and CoA components as the first step in the catabolism of acetyl-CoA to methane and CO2
-
-
?
CO + H2O
CO2 + H+ + electron
show the reaction diagram
-
-
-
r
CO + H2O
CO2 + H+ + electron
show the reaction diagram
-
the multienzyme complex catalyses the reversible oxidation of CO to CO2
-
r
CO + H2O
CO2 + H+ + electron
show the reaction diagram
P72021
the multienzyme complex catalyses the reversible oxidation of CO to CO2
-
r
CO + H2O
CO2 + H+ + electron
show the reaction diagram
-
the NiFe4S4-5C cluster catalyses the reversible oxidation of CO to CO2
-
r
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
-
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
-
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
-
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
-
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
-
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
?
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
-
-
?
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
show the reaction diagram
-
acetyl-CoA synthase catalyses acetyl-CoA synthesis, an intermediate step is the transfer of the cobalt-bound methyl group from methylated corrinoid/iron-sulfur protein to the acetyl-CoA synthase
-
?
CO2 + H+ + electron
CO + H2O
show the reaction diagram
-
CO dehydrogenase catalyses the two-electron reduction of CO2 to CO
-
?
additional information
?
-
-
enzyme catalyses the CoA/acetyl-CoA exchange
-
-
-
additional information
?
-
-
methylcobinamide, methylcobalamin, and CH3-(Me3-benzimidazolyl)cobamide are substrates of the acetyl-CoA synthase, methylcobalamin is 2000fold less reactive than methylcobinamide, CO dehydrogenase catalyses the CO-dependent reduction of methylcobinamide 10000fold faster than that of methylcobalamin
-
-
-
additional information
?
-
P72021
the multienzyme complex catalyses the exchange between free CO and carbonyl group of acetyl-CoA, and the exchange between CoA and the CoA moiety of acetyl-CoA
-
-
-
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
-
additional information
?
-
-
enzyme and a corrinoid/iron-sulfur protein, methyltransferase and an electron transfer protein such as ferredoxin II play a pivotal role in the conversion of methylhydrofolate, CO, and CoA to acetyl-CoA
-
-
-
additional information
?
-
-
the bifuctional enzyme CO dehydrogenase/acetyl-CoA synthase is central to the Wood-Ljungdahl pathway of autotrophic CO2 fixation
-
-
-
additional information
?
-
-
the enzyme catalyzes the exchange of 14C from the carboxyl group of acetyl-CoA with 12C from CO
-
-
-
additional information
?
-
P27988
CoA is the last substrate to bind and CO and the methyl group bind randomly as the first substrate in acetyl-CoA synthesis. In pulse-chase experiments, up to 100% of the methyl groups and CoA and up to 60-70% of the CO employed in the pulse phase can be trapped in the product acetyl-CoA
-
-
-
additional information
?
-
-
the purified carbon monoxide dehydrogenase, EC 1.2.7.4, from Clostridium thermoaceticum is the only protein required to catalyze a reversible exchange reaction between carbon monoxide and the carbonyl group of acetyl-CoA. Carbon dioxide also exchanges with the C-1 of acetyl-coA, but at a much lower rate than does CO
-
-
-
additional information
?
-
P27989
mechanism by which acetyl-CoA is assembled at the A-cluster and mechanism of CO2 reduction at the C-cluster, overview
-
-
-
additional information
?
-
-
an Fe/S-containing active site metal center, the A cluster, catalyzes acetyl CC bond formation/breakdown. Carbonyl group exchange of acetyl-CoA with CO is a hallmark of CODH/ACS, coupling analysis of the recombinant A cluster protein of acetyl-CoA synthase of Carboxydothermus hydrogenoformans, ACSCh, and truncated ACSCh lacking its 317-amino acid N-terminal domain, overview
-
-
-
additional information
?
-
-
an nickel-containing active site metal center, the A cluster, catalyzes acetyl C-C bond formation/breakdown. Carbonyl group exchange of acetyl-CoA with CO is weakly active in ACDS, and exchange with CO2 is up to 350 times faster, indicating tight coupling of CO release at the A cluster to CO oxidation to CO2 at the C cluster in CO dehydrogenase, coupling analysis of the recombinant A cluster protein of ACDS. Direct role of the ACS N-terminal domain in promoting acetyl C-C bond fragmentation. Protein conformational changes, related to open/closed states have direct effects on the coordination geometry and stability of the A cluster Ni2+-acetyl intermediate, controlling Ni2-acetyl fragmentation and Ni2(CO)(CH3) condensation. Involvement of subunit-subunit interactions in ACDS, versus interdomain contacts in ACS, ensures that CO is not released from the ACDS beta-subunit in the absence of appropriate interactions with the alpha2epsilon2 CO dehydrogenase component, ACDS complex partial reactions in the overall synthesis and cleavage of acetyl-CoA, overview
-
-
-
additional information
?
-
-
in assays of bacterial ACS, methylated corrinoid iron-sulfur protein is generally used as the source of methyl groups for acetyl-CoA synthesis
-
-
-
additional information
?
-
-
an nickel-containing active site metal center, the A cluster, catalyzes acetyl C-C bond formation/breakdown. Carbonyl group exchange of acetyl-CoA with CO is weakly active in ACDS, and exchange with CO2 is up to 350 times faster, indicating tight coupling of CO release at the A cluster to CO oxidation to CO2 at the C cluster in CO dehydrogenase, coupling analysis of the recombinant A cluster protein of ACDS. Direct role of the ACS N-terminal domain in promoting acetyl C-C bond fragmentation. Protein conformational changes, related to open/closed states have direct effects on the coordination geometry and stability of the A cluster Ni2+-acetyl intermediate, controlling Ni2-acetyl fragmentation and Ni2(CO)(CH3) condensation. Involvement of subunit-subunit interactions in ACDS, versus interdomain contacts in ACS, ensures that CO is not released from the ACDS beta-subunit in the absence of appropriate interactions with the alpha2epsilon2 CO dehydrogenase component, ACDS complex partial reactions in the overall synthesis and cleavage of acetyl-CoA, overview
-
-
-
additional information
?
-
Carboxydothermus hydrogenoformans DSM 6008
-
an Fe/S-containing active site metal center, the A cluster, catalyzes acetyl CC bond formation/breakdown. Carbonyl group exchange of acetyl-CoA with CO is a hallmark of CODH/ACS, coupling analysis of the recombinant A cluster protein of acetyl-CoA synthase of Carboxydothermus hydrogenoformans, ACSCh, and truncated ACSCh lacking its 317-amino acid N-terminal domain, overview
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
?
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
r
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
-
-
-
-
r
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
show the reaction diagram
Methanosarcina thermophila TM-1, Carboxydothermus hydrogenoformans DSM 6008
-
-
-
-
r
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
-
additional information
?
-
-
enzyme and a corrinoid/iron-sulfur protein, methyltransferase and an electron transfer protein such as ferredoxin II play a pivotal role in the conversion of methylhydrofolate, CO, and CoA to acetyl-CoA
-
-
-
additional information
?
-
-
the bifuctional enzyme CO dehydrogenase/acetyl-CoA synthase is central to the Wood-Ljungdahl pathway of autotrophic CO2 fixation
-
-
-
additional information
?
-
-
the purified carbon monoxide dehydrogenase, EC 1.2.7.4, from Clostridium thermoaceticum is the only protein required to catalyze a reversible exchange reaction between carbon monoxide and the carbonyl group of acetyl-CoA. Carbon dioxide also exchanges with the C-1 of acetyl-coA, but at a much lower rate than does CO
-
-
-
COFACTOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
Ferredoxin
-
Fd-II, which harbors two [4Fe-4S] clusters and is an electron acceptor for CODH, serves as a redox activator of ACS. Catalytic one-electron redox-active species in the CO/acetyl-CoA exchange reaction. Incubation of ACS with Fd-II and CO leads to the formation of the NiFeC species. FdII is purified from Moorella thermoacetica, overview
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
CO
-
a cobalt-containing Co/Fe-S component of multienzyme complex serves as a methyl carrier in the pathway of methane synthesis from acetate
CO
-
a cobalt-containing Co/Fe-S component of multienzyme complex serves as a methyl carrier in the pathway of methane synthesis from acetate
CO
-
cobalt is the active site for the methyltransfer reaction
Co3+
-
part of the methylcorrinoid protein
copper
-
the acetyl-CoA synthase active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site. Distorted Cu(I)-S3 site in the fully active enzyme in solution. Average Cu-S bond length of 2.25 A and a metal neighbor at 2.65 A, consistent with the Cu-Ni distance observed in the crystal structure. Cu-SCoA intermediate in the mechanism of acetyl-CoA synthesis. Essential and functional role for copper in the enzyme
Cu
-
the Ni in cluster A can be replaced by Cu yielding an inactive form of the acetyl-CoA synthase
Cu+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
Cu2+
P27989
the enzyme has a metallocofactor containing iron, sulfur, copper, and nickel, the cofactor responsible for the assembly of acetyl-CoA contains a [Fe4S4] cubane bridged to a copper-nickel binuclear site
Fe
-
corrinoid/iron-sulfur protein required
Fe
-
corrinoid/iron-sulfur protein required; the enzyme-bound complex can be described as an [NiFe3-4S4]-acetyl complex
Fe
-
corrinoid/iron-sulfur protein required; the multienzyme complex contains at least two protein components: a CO-oxidizing Ni/Fe-S component and a cobalt-containing Co/Fe-S component
Fe
P72021
a Ni/Fe-S cluster of multienzyme CO dehydrogenase/acetyl-CoA synthase complex is the active site of acetyl-CoA cleavage and synthesis; corrinoid/iron-sulfur protein required
Fe
-
corrinoid/iron-sulfur protein required; the Ni-Fe4S4-5C cluster of enzyme catalyses the reversible reduction of CO2 to CO and is located in the beta-subunit.
Fe
-
corrinoid/iron-sulfur protein required
Fe2+
P27989
the enzyme has a metallocofactor containing iron, sulfur, copper, and nickel, the cofactor responsible for the assembly of acetyl-CoA contains a [Fe4S4] cubane bridged to a copper-nickel binuclear site
Fe2+
-
Fe/S-containing active site metal center, the A cluster
Fe2+
-
a [Fe4S4] cluster
Iron
-
the acetyl-CoA synthase active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site
Iron
-
Mssbauer and EPR study of enzyme alpha-subunit. About 70% contain [Fe4S4]1+ cubanes, and 30% contain [Fe4S4]2+ cubanes suggesting an extremely low [Fe4S4] 1+/2+ reduction potential
Ni
-
the enzyme-bound complex can be described as an [NiFe3-4S4]-acetyl complex
Ni
-
the multienzyme complex contains at least two protein components: a CO-oxidizing Ni/Fe-S component and a cobalt-containing Co/Fe-S component
Ni
P72021
a Ni/Fe-S cluster of multienzyme CO dehydrogenase/acetyl-CoA synthase complex is the active site of acetyl-CoA cleavage and synthesis
Ni
-
enzyme contains nickel in the A-cluster of the enzyme; the Ni-Fe4S4-5C cluster of enzyme catalyses the reversible reduction of CO2 to CO and is located in the beta-subunit.
Ni
-
enzyme contains nickel in the A-cluster of the enzyme
Ni
-
the functional cluster A of ACSCh contains a Ni-Ni-[4Fe-4S] site, in which the position proximal and distal to the cubane are occupied by Ni ions
Ni2+
P27989
the enzyme has a metallocofactor containing iron, sulfur, copper, and nickel, instead of a [Fe4S4] cubane bridged to a mononuclear Ni site, the Ni is part of a Fe-[NiFe3S4] cluster
Ni2+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
Ni2+
-
formation of the NiFeC species
Ni2+
-
nickel-containing active site metal center, the A cluster, a binuclear Ni-Ni center bridged by a cysteine thiolate to an [Fe4S4] cluster. Ni2+-CO equatorial coordination environment in closed buried hydrophobic and open solvent-exposed states
Ni2+
-
required as reductant of the methylcorrinoid protein
Nickel
-
structural analogues of the bimetallic reaction center in acetyl CoA synthase: A Ni-Ni Model with bound CO
Nickel
-
the acetyl-CoA synthase active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site. Distorted Cu(I)-S3 site in the fully active enzyme in solution. Average Cu-S bond length of 2.25 A and a metal neighbor at 2.65 A, consistent with the Cu-Ni distance observed in the crystal structure
Nickel
-
two electrons are required for reductive activation of enzyme, starting from the oxidized state containing Ni2+. A Ni0 state may form upon reductive activation and reform after each catalytic cycle
Nickel
-
binding of Ni to the A-cluster slows the reduction kinetics of the [Fe4S4]2+ cubane. An upper limit of two electrons per a subunit are transferred from titanium(III) citrate to the Ni subcomponent of the A-cluster during reductive activation. These electrons are accepted quickly relative to the reduction of the [Fe4S4]2+ cubane. This reduction is probably a prerequisite for methyl group transfer
Nickel
-
synthesis of a dinuclear nickel complex with methyl and thiolate ligands, Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate)Ni(Me)(2,6-dimesitylphenyl) as a dinuclear Nid-Nip-site model of acetyl-CoA synthase. The reaction of Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate)Ni(Me)(2,6-dimesitylphenyl) withexcess CO affords the acetylthioester CH3C(O)-2,6-dimesitylphenyl with concomitant formation of Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate)Ni(CO)2 and Ni(CO)4 plus Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate). When complex Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate)Ni(Me)(2,6-dimesitylphenyl) is treated with 1 equiv of CO in the presence of excess 1,5-cyclooctadiene, the formation of Ni(N,N'-diethyl-3,7-diazanonane-1,9-dithiolate)Ni(CO)2 and Ni(CO)4 is considerably suppressed, and instead the dinuclear Ni(II)-Ni(0) complex is generated in situ. The results suggest that ACS catalysis could include the Nid(II)-Nip(0) state as the active species, that the Nid(II)-Nip(0) species could first react with methylcobalamin to afford Nid(II)-Nip(II)Me, and that CO insertion into the Nip-Me bond and the successive reductive elimination of acetyl-CoA occurs immediately when CoA is coordinated to the Nip site to form the active Nid(II)-Nip(0) species
Zn
-
the Ni in cluster A can be replaced by Zn yielding an inactive form of the acetyl-CoA synthase
Zn2+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
Iron
-
binding of Ni to the A-cluster slows the reduction kinetics of the [Fe4S4]2+ cubane. An upper limit of two electrons per a subunit are transferred from titanium(III) citrate to the Ni subcomponent of the A-cluster during reductive activation. These electrons are accepted quickly relative to the reduction of the [Fe4S4]2+ cubane. This reduction is probably a prerequisite for methyl group transfer
additional information
-
a nucleophilic metal center on enzyme is the active site which accepts the methyl group from the methylated corrinoid/iron-sulfur protein
additional information
-
Cu is not required for enzyme activity
additional information
-
Ti3+ NTAis utilized in the CO exchange assay
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
CN-
-
inhibitor on the CoA/acetyl-CoA exchange, 98% inhibition at 1.2 mM
CO
-
non-competitive inhibitor on the CoA/acetyl-CoA exchange, the Ni-Fe-C-center appears to be the inhibitor site for CO
CO
-
inhibits the methyl group transfer reaction and synthesis of acetyl-CoA
CO
-
the complete alpha2beta2 enzyme exhibits strong cooperative inhibition, isolated alpha is weakly inhibited, apparently by a single CO with Ki = 1.5 mM. Absence of strong cooperative inhibition of CO in mutant enzymes A265M and AA110C
CO2
-
inhibitor on the CoA/acetyl-CoA exchange
CoA
-
at concentration above 10 mM, 50% inhibition of acetyl-CoA synthesis from methyl iodide at 15 mM
dephospho-CoA
-
inhibitor on the CoA/acetyl-CoA exchange, 75% inhibition at 0.44 mM
desulfo-CoA
-
inhibitor on the CoA/acetyl-CoA exchange, 30% mM at 2.1 mM
Dithionite
-
inhibits reverse methyl group transfer, when it is preincubated with methylated enzyme but not when it is preincubated with Co+-iron-sulfur protein
Fe2+
-
in cofactor ferredoxin(II), which harbors two [4Fe-4S] clusters
-
Mersalyl acid
-
inhibits the acetyl-CoA/CO exchange reaction
N2O
-
inhibitor on the CoA/acetyl-CoA exchange
S,S-dithiobis-(2-nitrobenzoate)
-
inhibits the acetyl-CoA/CO exchange reaction
-
Sodium dithionite
-
inhibits the acetyl-CoA/CO exchange reaction
Ti3+-citrate
-
inhibits reverse methyl group transfer, when it is preincubated with methylated enzyme but not when it is preincubated with Co+-iron-sulfur protein
-
Methyl iodide
-
inhibits the acetyl-CoA/CO exchange reaction
additional information
-
no inhibition of the exchange reaction by methyl- and phenylglyoxal, and butanedione
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
CO
-
two effects: stimulation and inhibition on CoA/acetylCoA exchange
Ferredoxin
-
stimulates the rate of synthesis of acetyl-CoA 4fold, Km is 0.0034 mM
-
Ferredoxin
-
stimulation of acetyl-CoA synthesis from methyl iodide, maximum at 1 nmol ferredoxin/15 nmol of enzyme
-
additional information
-
neither ATP nor phosphate stimulate the exchange
-
additional information
-
reductive activation of the enzyme by ferrdoxin, mechanism, detailed overview
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.28
-
acetyl-CoA
-
exchange activity: C14 from the carboxyl group of acetyl-CoA with C12 from CO
14.7
-
CH3I
-
pH 7.3, 22C
0.087
-
CO
-
pH 7.2, 25C, recombinant ACSD beta
0.36
-
CO
-
pH 7.2, 25C, recombinant ACSChDELTAN
4.3
-
CoA
-
pH 7.3, 22C, acetyl-CoA synthesis from methyl iodide
0.066
-
methylcorrinoid protein
-
pH 7.2, 25C, recombinant ACSChDELTAN
0.46
-
methylcorrinoid protein
-
pH 7.2, 25C, recombinant ACSCh732
0.53
-
methylcorrinoid protein
-
pH 7.2, 25C, recombinant ACSD beta
additional information
-
additional information
-
kinetics of recombinant ACSCh732 and ACSChDELTAN for acetyl-CoA synthase activity, acetyltransferase activity, and acetyl-CoA/CO exchange activity, overview
-
additional information
-
additional information
-
kinetics of recombinant ACSD beta for acetyl-CoA synthase activity, acetyltransferase activity, and acetyl-CoA/CO exchange activity, overview
-
additional information
-
additional information
-
kinetics, overview
-
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.00012
-
acetyl-CoA
-
pH 7.2, 25C, recombinant ACSChDELTAN, acetyl-CoA/CO exchange activity
0.0002
-
acetyl-CoA
-
pH 7.2, 25C, recombinant ACSD beta, acetyl-CoA/CO exchange activity
0.142
-
acetyl-CoA
-
pH 7.2, 25C, recombinant ACSCh732, acetyl-CoA/CO exchange activity
additional information
-
additional information
-
-
-
additional information
-
additional information
-
stopped-flow analysis of two steps within the catalytic cycle
-
Ki VALUE [mM]
Ki VALUE [mM] Maximum
INHIBITOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.4
-
CO
-
pH 7.0, 25C, under anaerobic conditions, noncompetitive with respect to acetyl-CoA
1.5
-
CO
-
the complete alpha2beta2 enzyme exhibits strong cooperative inhibition, isolated alpha is weakly inhibited, apparently by a single CO with Ki = 1.5 mM
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.12
-
-
pH 6.8, acetyl-CoA synthesis, in absence of ferredoxin II
0.41
-
-
pH 6.8, acetyl-CoA synthesis, in presence of 1 mM ferrous ammonium sulfate
0.49
-
-
pH 6.8, acetyl-CoA synthesis, in presence of ferredoxin II
0.74
-
-
pH 6.8, acetyl-CoA synthesis, in presence of 4 mM ATP
0.8
-
-
pH 6.8, acetyl-CoA synthesis, in absence of ATP and Fe2+
28
-
-
40C, CoA/acetyl-CoA exchange
additional information
-
-
70 mol of CO exchanged per min/mol of enzyme
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
5.4
-
-
CO/acetyl-CoA exchange reaction
5.8
-
-
Tris-maleate buffer, the rate of acetyl-CoA synthesis increases with decreasing pH, at pH values below 5.8 the rate of acetyl-CoA synthesis decreases slightly
6
-
-
exchange activity: C14 from the carboxyl group of acetyl-CoA with C12 from CO
6.2
-
-
acetyl-CoA exchange assay at
6.5
-
-
CO exchange assay at
6.7
7
-
optimum for CoA/acetyl-CoA exchange
6.7
7.2
-
assay at
6.7
-
-
acetyltransferase assay at
7.2
-
-
acetyl-CoA synthase assay at
7.2
-
-
acetyl-CoA synthesis assay at
7.6
-
-
methylation reaction assay at
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
22
-
-
acetyl-CoA exchange assay at room temperature
25
-
-
acetyl-CoA synthesis and CO exchange assay at
45
-
-
methylation reaction assay at
70
-
-
exchange activity: C14 from the carboxyl group of acetyl-CoA with C12 from CO
TEMPERATURE RANGE
TEMPERATURE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
35
-
in 10 mM Tris-maleate buffer and pH 5.8, the rate of acetyl-CoA synthesis is increased 2fold at 25C to 35C
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
-
cultures are grown on methanol, acetate, or CO
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
81700
-
-
gel filtration
310000
-
P27989
-
1600000
-
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
heterotetramer
-
CODH and ACS make up the two subunits of a 310 kDa alpha2beta2 heterotetrameric enzymatic complex
polymer
-
alpha,beta,gamma,delta,epsilon, 6 * 19700 + 6 * 84500 + 6 * 63200 + 6 * 53000 + 6 * 51400, SDS-PAGE
tetramer
P27989
alpha2beta2 heterotetramer, the beta2 domains form the center of the complex
tetramer
-
alpha,beta, containing two unique Ni-Fe-S active sites connected by a molecular tunnel
monomer
-
1 * 82900, the enzyme exists as a monomer as well as in a 1:1 molar complex with the 73300 Da CO dehydrogenase III, SDS-PAGE
additional information
P27989
overall enzyme structure, channels, and protein-protein interactions, the beta domains are responsible for CO2/CO chemistry and contain the B-, C-, and D-clusters, detailed overview
additional information
P72021
alpha,beta,gamma,delta,epsilon, the enzyme complex is part of a five-subunit complex, the alpha and epsilon subunits are required for CO oxidation, the gamma end delta subunits constitute a corrinoid/iron-sulfur protein, the beta subunit harbors the Ni/Fe-S cluster, that is the active site of acetyl-CoA cleavage/synthesis, the interaction between the alpha,epsilon dimer and the beta subunit is necessary for breaking and forming the C-C bond of acetyl-CoA, SDS-PAGE
additional information
-
open and closed conformations of ACS, overview
additional information
-
open and closed conformations of ACS, overview
-
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
49 kDa fragment containing residues 311-729 of the intact enzym. In the fragment, domains A2 and A3 have significantlymoved to each other, corresponding to a rotation around a hinge region located close to the C-terminus of the long interdomain helix; crystal structure of recombinant ACS lacking the N-terminal domain that interacts with carbon monoxide dehydrogenase shows a large reorganization of the remaining two globular domains, producing a narrow cleft of suitable size, shape, and nature to bind CoA. Sequence comparisons with homologous archaeal enzymes that naturally lack the N-terminal domain show that many amino acids lining this cleft are conserved. Besides the typical [4Fe-4S] center, the A-cluster contains only one proximal metal ion that is most likely Cu or Zn. Incorporation of a functional Ni2Fe4S4 A-cluster would require only minor structural rearrangements
-
a 2.5 A resolution structure of xenon-pressurized CODH/ACS, examination of the nature of gaseous cavities within the enzyme. The cavity calculation program CAVENV accurately predicts the channels connecting the C- and A-clusters, with 17 of 19 xenon binding sites within the predicted regions. The enzyme has a channel for a small substrate, a channel plug, a flexible acetyl-CoA synthase subunit that can open to interact with a large substrate, and an interdomain cavity to putatively bind a medium-sized substrate
-
sitting drop vapor diffusion at room temperature in a Coy anaerobic chamber, 0.005 ml of protein solution containing 40-60 mg/ml CODH/ACS in 50 mM Tris, pH 7.6, are mixed with 0.0075 ml of reservoir solution containing 8% polyethylene glycol MME 5000, 20% glycerol, 200 mM calcium acetate, 100 mM PIPES, pH 6.5, and 2 mM dithioerythritol, X-ray diffraction structure determination and analysis at 2.2 A resolution, multiwavelength anomalous dispersion techniques, molecular replacement
P27989
structures of the 310 kDa bifunctional CODH/acetyl-CoA synthase complex bound both with a substrate H2O/OH- molecule and with a cyanide inhibitor. Both in native crystals and identical crystals soaked in a solution containing potassium cyanide, the substrateH2O/OH- molecule exhibits binding to the unique Fe site of the C-cluster. Cyanide binding is also observed in a bent conformation to Ni of the C-cluster, adjacent the substrate H2O/OH-molecule. The bridging sulfide is not present in either structure. Findings do not support a fifth, bridging sulfide playing a catalytic role in the enzyme mechanism
-
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
67
-
-
the recombinant enzyme: 10 min, 10% loss of activity, the wild-type enzyme: 10 min, no loss of activity
75
-
-
the wild-type enzyme: 10 min, 50% loss of activity
GENERAL STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
reactions in presence of DTT, since enzyme requires strictly anaerobic conditions for stability
-
the acetyl-CoA synthesis is dependent on ionic strength, the CO/acetyl-CoA exchange is independent of ionic strength
-
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
recombinant ACSCh732 and ACSChDELTAN from Escherichia coli strain NM522 by anion exchange and hydroxyapatite chromatography, followed by another and different step of anion exchange chromatography and by hydrophobic interaction chromatography to 94-95% purity forACSCh and around 98% purity for ACSChDELTAN
-
recombinant ACSD beta from Escherichia coli strain NM522 by anion exchange chromatography, followed by hydrophobic interaction chromatography and another and different step of ion exchange of anion exchange chromatography to around 98% purity for ACDS beta
-
native enzyme by anion exchange and hydrophobic interaction chromatography, followed by hydroxylapatite chromatography, gel filtration, and CoA affinity chromatography
-
recombinant C-terminally His-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography under a N2 atmosphere
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
gene ascB, expression of full-length protein, designated ACSCh732 amino acids, and as a form lacking the 317-amino acid N-terminal domain, designated ACSChDELTAN, 415 amino acids, in Escherichia coli strain NM522
-
two putative operons encoding CODH/ACS, designated cdh1 (ma1016-ma1011) and cdh2 (ma3860-ma3865), both encoding bona fide CODH/ACS isoforms, as well as cdhA3 (ma4399), isogenes organisation, expression of the Cdh2-encoding genes is generally higher than that of genes encoding Cdh1, expression of cdh1, cdh2, and cdhA1 in Escherichia coli
-
expression of ACSD beta in Escherichia coli strain NM522
-
expression in Escherichia coli
-
expression of a 49 kDa fragment containing residues 311-729 of the intact enzyme and a C-terminal His tag, in Escherichia coli
-
expression of C-terminally His-tagged enzyme in Escherichia coli strain BL21(DE3) from a pet29a(+) vector
-
the gene has been cloned into Escherichia coli and found to be within an 11 kb gene cluster, recombinant enzyme is inactive
-
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
A110C
-
absence of strong cooperative inhibition of CO which characterizes wild-type enzyme
A110C
-
mutant designed to block the CO-migrating tunnel in the alpha-subunit. Electron paramagnetic resonance spectra indicates that the A-cluster is properly assembled. ACS activity is similar to that of the wild-type recombinant Ni-activated alpha-subunit
A219F
-
mutant designed to block the tunnel through which CO and CO2 migrate. Metal clusters are properly assembled but only slowly reducible by CO. Mutant shows impaired ability of CO to migrate through the tunnel to the C-cluster and reduced catalytic activity, no cooperative CO inhibition is observed
A222L
-
the bifunctional mutant enzyme is not able to synthesize acetyl-CoA using CO2 as substrate
A222L
-
mutant designed to block the CO-migrating tunnel in the alpha-subunit. Electron paramagnetic resonance spectra indicates that the A-cluster is properly assembled. ACS activity is similar to that of the wild-type recombinant Ni-activated alpha-subunit
A265M
-
absence of strong cooperative inhibition of CO which characterizes wild-type enzyme
A578C
-
mutant designed to block the tunnel through which CO and CO2 migrate. Metal clusters are properly assembled but only slowly reducible by CO. Mutant shows impaired ability of CO to migrate through the tunnel to the C-cluster and reduced catalytic activity, no cooperative CO inhibition is observed
F70W
-
mutant designed to block the region that connects the tunnel at the betabeta interface with a water channel also located at the interface. Metal clusters are properly assembled but only slowly reducible by CO. Mutant shows impaired ability of CO to migrate through the tunnel to the C-cluster and reduced catalytic activity, no cooperative CO inhibition is observed
L215F
-
mutant designed to block the tunnel through which CO and CO2 migrate. Metal clusters are properly assembled but only slowly reducible by CO. Mutant shows impaired ability of CO to migrate through the tunnel to the C-cluster and reduced catalytic activity, no cooperative CO inhibition is observed
N101Q
-
mutant designed to block the region that connects the tunnel at the betabeta interface with a water channel also located at the interface. Metal clusters are properly assembled but only slowly reducible by CO. Mutant shows impaired ability of CO to migrate through the tunnel to the C-cluster and reduced catalytic activity, no cooperative CO inhibition is observed
additional information
-
construction of several cdh gene knockouts, genotypic and phenotypic analysis of cdh mutants. CODH activity during aceticlastic and carboxidotrophic growth is reduced in the cdh1 mutant (strain MCD1) compared to the wild-type
Renatured/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
purified recombinant ACS is Ni-reconstituted in the elution buffer with 6 equivalents of NiCl2 for 2 or 3 days at 27C or at 45C
-