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Information on EC 2.3.1.169 - CO-methylating acetyl-CoA synthase and Organism(s) Moorella thermoacetica and UniProt Accession P27988
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2.3.1.169 CO-methylating acetyl-CoA synthaseIUBMB Comments
Contains nickel, copper and iron-sulfur clusters. Involved, together with EC 1.2.7.4, carbon-monoxide dehydrogenase (ferredoxin), in the synthesis of acetyl-CoA from CO2 and H2.
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Word Map
- 2.3.1.169
- methanosarcina
- thermophila
- acetylthiocholine
-
methyl-coenzyme
-
methanogenesis
- butyrylthiocholine
-
busch
-
base-off
- propionylthiocholine
-
nickel-containing
-
moorella
- azinphos-methyl
- acetivorans
-
2-naphthyl
- thermoacetica
-
bioorganometallic
-
five-subunit
- methylcobalamin
-
acetate-grown
The taxonomic range for the selected organisms is: Moorella thermoacetica
The enzyme appears in selected viruses and cellular organisms
The enzyme appears in selected viruses and cellular organisms
Reaction Schemes
+
a [Co(I) corrinoid Fe-S protein]
=
+
+
a [methyl-Co(III) corrinoid Fe-S protein]
Synonyms
acsch, co dehydrogenase enzyme complex, carbon monoxide dehydrogenase/acetyl-coenzyme a synthase, carbon monoxide dehydrogenase/acetyl coenzyme a synthase, co-methylating acetyl-coa synthase, co dehydrogenase/acetyl coa synthase, multienzyme carbon monoxide dehydrogenase complex, 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
acetyl-CoA decarboxylase/synthase
-
-
-
-
Acetyl-CoA synthase
-
-
-
-
Acetyl-coenzyme A synthase
-
-
-
-
Carbon monoxide dehydrogenase
-
-
-
-
carbon monoxide dehydrogenase-corrinoid enzyme complex
-
-
-
-
carbon monoxide dehydrogenase/acetyl-CoA synthase
CO dehydrogenase
-
-
-
-
CO dehydrogenase enzyme complex
-
-
-
-
CODH
-
-
-
-
CODH/ASC
-
-
-
-
multienzyme carbon monoxide dehydrogenase complex
-
-
-
-
multienzyme CO dehydrogenase/acetyl-CoA synthase complex
-
-
-
-
carbon monoxide dehydrogenase/acetyl-CoA synthase
-
-
-
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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 + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
pathway
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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 + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
the FeS cluster is present to relay electrons from enzyme to CO
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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.
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
the transfer of methyl group to enzyme occurs by SN2-type nucleophilic displacement, not a radical, reaction
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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 + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
the enzyme-bound complex is an [NiFe3-4S4]-acetyl complex
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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 + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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 + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
CO migrates to the A-cluster through two pathways, one involving and one not involving the tunnel
-
acetyl-CoA + a [Co(I) corrinoid Fe-S protein] = CO + CoA + a [methyl-Co(III) corrinoid Fe-S protein]
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
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
demethylation
-
-
-
-
PATHWAY SOURCE
PATHWAYS
-
-, -
SYSTEMATIC NAME
IUBMB Comments
acetyl-CoA:corrinoid protein O-acetyltransferase
Contains nickel, copper and iron-sulfur clusters. Involved, together with EC 1.2.7.4, carbon-monoxide dehydrogenase (ferredoxin), in the synthesis of acetyl-CoA from CO2 and H2.
CAS REGISTRY NUMBER
COMMENTARY
176591-19-8
-
64972-88-9
-
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
CO2 + H+ + electron
CO + H2O
-
CO dehydrogenase catalyses the two-electron reduction of CO2 to CO
-
?
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
-
-
-
-
?
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
-
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
-
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
-
-
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
-
under anaerobic conditions
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
-
under anaerobic conditions
-
?
CH3-(corrinoid/iron-sulfur protein) + CO + HS-CoA
CH3-CO-S-CoA + corrinoid/iron-sulfur protein
-
under anaerobic conditions
-
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
-
-
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
-
-
-
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
-
-
-
?
CH3-tetrahydrofolate + CO + HS-CoA
CH3-CO-S-CoA + tetrahydrofolate
-
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
-
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.
-
?
CO + H2O
CO2 + H+ + electron
-
the multienzyme complex catalyses the reversible oxidation of CO to CO2
-
r
CO + H2O
CO2 + H+ + electron
-
the NiFe4S4-5C cluster catalyses the reversible oxidation of CO to CO2
-
r
CO + methyl-X + HS-CoA
CH3-CO-S-CoA + HX
-
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
-
?
additional information
?
-
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
?
-
-
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
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
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
-
-
?
additional information
?
-
mechanism by which acetyl-CoA is assembled at the A-cluster and mechanism of CO2 reduction at the C-cluster, overview
-
-
?
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
acetyl-CoA + corrinoid protein
CoA + CO + methylcorrinoid protein
-
-
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
additional information
?
-
-
key enzyme in the autotrophic acetyl-CoA pathway, i.e. Wood pathway, enzyme catalyses the final steps in this pathway
-
-
?
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
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
COMMENTARY
LITERATURE
CO
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+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
Cu2+
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
Fe2+
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
Iron
Ni
Ni2+
Nickel
Zn2+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
additional information
CO
-
a cobalt-containing Co/Fe-S component of multienzyme complex serves as a methyl carrier in the pathway of methane synthesis from acetate
Fe
-
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
Fe
-
the enzyme-bound complex can be described as an [NiFe3-4S4]-acetyl complex
Iron
-
the acetyl-CoA synthase active site contains a [4Fe-4S] cluster bridged to a binuclear Cu-Ni site
Iron
-
Mössbauer 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
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
Ni
-
the Ni-Fe4S4-5C cluster of enzyme catalyses the reversible reduction of CO2 to CO and is located in the beta-subunit.
Ni
-
the enzyme-bound complex can be described as an [NiFe3-4S4]-acetyl complex
Ni
-
enzyme contains nickel in the A-cluster of the enzyme
Ni2+
-
capture of Ni2+, Cu+ and Zn2+ by thiolate sulfurs of an N2S2Ni complex
Ni2+
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
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
additional information
-
a nucleophilic metal center on enzyme is the active site which accepts the methyl group from the methylated corrinoid/iron-sulfur protein
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
5,5'dithiobis-(2-nitrobenzoic acid)
-
inhibits the acetyl-CoA/CO exchange reaction
CN-
-
inhibitor on the CoA/acetyl-CoA exchange, 98% inhibition at 1.2 mM
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
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
additional information
-
no inhibition of the exchange reaction by methyl- and phenylglyoxal, and butanedione
-
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
ACTIVATING COMPOUND
ORGANISM
UNIPROT
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]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
additional information
additional information
-
stopped-flow analysis of two steps within the catalytic cycle
-
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.4
CO
-
pH 7.0, 25°C, 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]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
0.41
-
pH 6.8, acetyl-CoA synthesis, in presence of 1 mM ferrous ammonium sulfate
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
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
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
25 - 35
-
in 10 mM Tris-maleate buffer and pH 5.8, the rate of acetyl-CoA synthesis is increased 2fold at 25°C to 35°C
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
physiological function
additional information
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
physiological function
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
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). PDB
SCOP
CATH
UNIPROT
ORGANISM
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
heterotetramer
-
CODH and ACS make up the two subunits of a 310 kDa alpha2beta2 heterotetrameric enzymatic complex
tetramer
additional information
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
tetramer
-
alpha,beta, containing two unique Ni-Fe-S active sites connected by a molecular tunnel
tetramer
alpha2beta2 heterotetramer, the beta2 domains form the center of the complex
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
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
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
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
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
-
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
A110C
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
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
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
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
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
67
-
the recombinant enzyme: 10 min, 10% loss of activity, the wild-type enzyme: 10 min, no loss of activity
GENERAL STABILITY
ORGANISM
UNIPROT
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
LITERATURE
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
LITERATURE
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
-
RENATURED/Commentary
ORGANISM
UNIPROT
LITERATURE
purified recombinant ACS is Ni-reconstituted in the elution buffer with 6 equivalents of NiCl2 for 2 or 3 days at 27°C or at 45°C
-
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Ragsdale, S.W.; Wood, H.G.
Acetate biosynthesis by acetogenic bacteria. Evidence that carbon monoxide dehydrogenase is the condensing enzyme that catalyzes the final steps of the synthesis
J. Biol. Chem.
260
3970-3977
1985
Moorella thermoacetica
Lu, W.P.; Ragsdale, S.W.
Reductive activation of the coenzyme A/acetyl-CoA isotopic exchange reaction catalyzed by carbon monoxide dehydrogenase from Clostridium thermoaceticum and its inhibition by nitrous oxide and carbon monoxide
J. Biol. Chem.
266
3554-3564
1991
Moorella thermoacetica
Roberts, J.R.; Lu, W.P.; Ragsdale, S.W.
Acetyl-coenzyme A synthesis from methyltetrahydrofolate, CO, and coenzyme A by enzymes purified from Clostridium thermoaceticum: Attainment of in vivo rates and identification of rate-limiting steps
J. Bacteriol.
174
4667-4676
1992
Moorella thermoacetica
Menon, S.; Ragsdale, S.W.
Role of the [4Fe-4S] cluster in reductive activation of the cobalt center of the corrinoid iron-sulfur protein from Clostridium thermoaceticum during acetate biosynthesis
Biochemistry
37
5689-5698
1998
Moorella thermoacetica
Doukov, T.I.; Iverson, T.M.; Seravalli, J.; Ragsdale, S.W.; Drennan, C.L.
A Ni-Fe-Cu center in a bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase
Science
298
567-572
2002
Moorella thermoacetica (P27989)
Lu, W.P.; Harder, S.R.; Ragsdale, S.W.
Controlled potential enzymology of methyl transfer reactions involved in acetyl-CoA synthesis by CO dehydrogenase and the corrinoid/iron-sulfur protein from Clostridium thermoaceticum
J. Biol. Chem.
265
3124-3133
1990
Moorella thermoacetica
Roberts, D.L.; James-Hagstrom, J.E.; Garvin, D.K.; Gorst, C.M.; Runquist, J.A.; Baur, J.R.; Haase, F.C.; Ragsdale, S.W.
Cloning and expression of the gene cluster encoding key proteins involved in acetyl-CoA synthesis in Clostridium thermoaceticum: carbon monoxide dehydrogenase, the corrinoid/iron-sulfur protein, and methyltransferase
Proc. Natl. Acad. Sci. USA
86
32-36
1989
Moorella thermoacetica
Kasmi, A.E.; Rajasekharan, S.; Ragsdale, S.W.
Anaerobic pathway for conversion of the methyl group of aromatic methyl ethers to acetic acid by Clostridium thermoaceticum
Biochemistry
33
11217-11224
1994
Moorella thermoacetica
Menon, S.; Ragsdale, S.W.
The role of an iron-sulfur cluster in an enzymic methylation reaction: Methylation of CO dehydrogenase/acetyl-CoA synthase by the methylated corrinoid iron-sulfur protein
J. Biol. Chem.
274
11513-11518
1999
Moorella thermoacetica
Tan, X.S.; Sewell, C.; Lindahl, P.A.
Stopped-flow kinetics of methyl group transfer between the corrinoid-iron-sulfur protein and acetyl-Coenzyme A synthase from Clostridium thermoaceticum
J. Am. Chem. Soc.
124
6277-6284
2002
Moorella thermoacetica
Tan, X.; Sewell, C.; Yang, Q.; Lindahl, P.A.
Reduction and methyl transfer kinetics of the a subunit from acetyl Coenzyme A synthase
J. Am. Chem. Soc.
125
318-319
2003
Moorella thermoacetica
Bramlett, M.R.; Tan, X.; Lindahl, P.A.
Inactivation of acetyl-CoA synthase/carbon monoxide dehydrogenase by copper
J. Am. Chem. Soc.
125
9316-9317
2003
Moorella thermoacetica
Seravalli, J.; Brown, K.L.; Ragsdale, S.W.
Acetyl Coenzyme A synthesis from unnatural methylated corrinoids: Requirement for "Base-Off" coordination at cobalt
J. Am. Chem. Soc.
123
1786-1787
2001
Moorella thermoacetica, Methanosarcina barkeri
Tan, X.; Loke, H.K.; Fitch, S.; Lindahl, P.A.
The tunnel of acetyl-coenzyme A synthase/carbon monoxide dehydrogenase regulates delivery of CO to the active site
J. Am. Chem. Soc.
127
5833-5839
2005
Moorella thermoacetica
Golden, M.L.; Rampersad, M.V.; Reibenspies, J.H.; Darensbourg, M.Y.
Capture of NiII, CuI and ZnII by thiolate sulfurs of an N2S2Ni complex: A role for a metallothiolate ligand in the acetyl-coenzyme A synthase active site
Chem. Commun. (Camb.)
2003
1824-1825
2003
Moorella thermoacetica
-
Linck, R.C.; Spahn, C.W.; Rauchfuss, T.B.; Wilson, S.R.
Structural analogues of the bimetallic reaction center in acetyl CoA synthase: A Ni-Ni Model with bound CO
J. Am. Chem. Soc.
125
8700-8701
2003
Moorella thermoacetica
Seravalli, J.; Gu, W.; Tam, A.; Strauss, E.; Begley, T.P.; Cramer, S.P.; Ragsdale, S.W.
Functional copper at the acetyl-CoA synthase active site
Proc. Natl. Acad. Sci. USA
100
3689-3694
2003
Moorella thermoacetica
Bramlett, M.R.; Stubna, A.; Tan, X.; Surovtsev, I.V.; Muenck, E.; Lindahl, P.A.
Moessbauer and EPR study of recombinant acetyl-CoA synthase from Moorella thermoacetica
Biochemistry
45
8674-8685
2006
Moorella thermoacetica
Tan, X.; Surovtsev, I.V.; Lindahl, P.A.
Kinetics of CO insertion and acetyl group transfer steps, and a model of the acetyl-CoA synthase catalytic mechanism
J. Am. Chem. Soc.
128
12331-12338
2006
Moorella thermoacetica
Tan, X.; Volbeda, A.; Fontecilla-Camps, J.C.; Lindahl, P.A.
Function of the tunnel in acetylcoenzyme A synthase/carbon monoxide dehydrogenase
J. Biol. Inorg. Chem.
11
371-378
2006
Moorella thermoacetica
Doukov, T.I.; Blasiak, L.C.; Seravalli, J.; Ragsdale, S.W.; Drennan, C.L.
Xenon in and at the end of the tunnel of bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase
Biochemistry
47
3474-3483
2008
Moorella thermoacetica
Seravalli, J.; Ragsdale, S.W.
Pulse-chase studies of the synthesis of acetyl-CoA by carbon monoxide dehydrogenase/acetyl-CoA synthase: evidence for a random mechanism of methyl and carbonyl addition
J. Biol. Chem.
283
8384-8394
2008
Moorella thermoacetica (P27988)
Tan, X.; Lindahl, P.A.
Tunnel mutagenesis and Ni-dependent reduction and methylation of the alpha subunit of acetyl coenzyme A synthase/carbon monoxide dehydrogenase
J. Biol. Inorg. Chem.
13
771-778
2008
Moorella thermoacetica
Kung, Y.; Doukov, T.I.; Seravalli, J.; Ragsdale, S.W.; Drennan, C.L.
Crystallographic snapshots of cyanide- and water-bound C-clusters from bifunctional carbon monoxide dehydrogenase/acetyl-CoA synthase
Biochemistry
48
7432-7440
2009
Moorella thermoacetica
Volbeda, A.; Darnault, C.; Tan, X.; Lindahl, P.A.; Fontecilla-Camps, J.C.
Novel domain arrangement in the crystal structure of a truncated acetyl-CoA synthase from Moorella thermoacetica
Biochemistry
48
7916-7926
2009
Moorella thermoacetica, Moorella thermoacetica (P27988)
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