Information on EC 1.4.9.1 - methylamine dehydrogenase (amicyanin)

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The enzyme appears in viruses and cellular organisms

EC NUMBER
COMMENTARY hide
1.4.9.1
-
RECOMMENDED NAME
GeneOntology No.
methylamine dehydrogenase (amicyanin)
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
methylamine + H2O + 2 amicyanin = formaldehyde + NH3 + 2 reduced amicyanin
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Deamination
-
-
oxidation
-
-
-
-
oxidative deamination
-
-
-
-
redox reaction
-
-
-
-
reduction
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
methylamine degradation I
-
-
Methane metabolism
-
-
Microbial metabolism in diverse environments
-
-
SYSTEMATIC NAME
IUBMB Comments
methylamine:amicyanin oxidoreductase (deaminating)
Contains tryptophan tryptophylquinone (TTQ) cofactor. The enzyme oxidizes aliphatic monoamines and diamines, histamine and ethanolamine, but not secondary and tertiary amines, quaternary ammonium salts or aromatic amines.
CAS REGISTRY NUMBER
COMMENTARY hide
55476-92-1
-
60496-14-2
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
Methylobacterium extorquens ATCC 14718 / DSM 1338 / JCM 2805 / NCIMB 9133 / AM1
AM1
-
-
Manually annotated by BRENDA team
Mycobacterium convolutum
inducible enzyme
-
-
Manually annotated by BRENDA team
K95
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
-
the qhp genes are very widely distributed, not only in many Gram-negative species but also in a few Gram-positive bacteria, bacterial distribution of qhp and associated genes, overview. The subunits constituting QHNDH are encoded by ORF1 (alpha subunit), ORF4 (beta subunit), and ORF3 (gamma subunit). Of the other genes in the operon, ORF2 encodes an [Fe-S] cluster and S-adenosylmethionine (SAM)-binding protein, a member of the radical SAM superfamily, and ORF5 encodes a protein of approximately 22.5 kDa belonging to subfamily S8A of peptidase family S8 (the subtilisin family) with the conserved Asp/His/Ser catalytic triad characteristic of this subfamily
malfunction
-
the genes mauF and mauE are membrane proteins with no homology to characterized proteins, and are thought to be involved in transport of MADH subunits into the periplasm. Knocking out either gene leads to no detectable beta-subunit in the periplasm, and an unusual beta-subunit leader sequence is consistent with it being trafficked by a specific transporter. The loss of mauF and mauE additionally leads to a drastic reduction in alpha-subunit. The third gene, mauD, is homologous to disulfide isomerases, and is likely specific to the MADH beta-subunit, which has six disulfides. In the absence of mauD, periplasmic alpha-subunit levels are close to normal, but again there is no detectable beta-subunit implying that the disulfides are key to beta-subunit stability. When the final required gene, mauG, is knocked out, there are normal levels of MADH alpha- and beta-subunit in the periplasm, but no methylamine dehydrogenase activity is present. This has focused attention on the mauG gene product as a likely participant in TTQ biosynthesis
physiological function
additional information
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
1,12-diaminododecane + acceptor + H2O
? + NH3 + reduced acceptor
show the reaction diagram
-
-
-
-
?
1,6-diaminohexane + acceptor + H2O
?
show the reaction diagram
-
acceptor: phenazine ethosulfate/2,6-dichlorophenolindophenol
-
-
?
1,7-diaminoheptane + acceptor + H2O
?
show the reaction diagram
-
acceptor: phenazine ethosulfate/2,6-dichlorophenolindophenol
-
-
?
1,8-diaminooctane + H2O + acceptor
?
show the reaction diagram
1-aminopentane + acceptor + H2O
pentanal + NH3 + H2O2
show the reaction diagram
-
acceptor: phenazine ethosulfate/2,6-dichlorophenolindophenol
-
-
?
1-aminopentane + acceptor + H2O
pentanal + NH3 + reduced acceptor
show the reaction diagram
-
acceptor: phenazine ethosulfate/2,6-dichlorophenolindophenol
-
-
?
12-aminododecane + acceptor + H2O
dodecanal + NH3 + reduced acceptor
show the reaction diagram
-
-
-
-
?
2-phenylethylamine + 2 H2O + 2 acceptor
2-phenylacetic acid + NH3 + 2 reduced acceptor
show the reaction diagram
-
primary amine
-
-
?
2-phenylethylamine + acceptor + H2O
2-phenylacetaldehyde + NH3 + reduced acceptor
show the reaction diagram
-
acceptor: phenazine ethosulfate/2,6-dichlorophenolindophenol
-
-
?
benzylamine + acceptor + H2O
benzaldehyde + NH3 + reduced acceptor
show the reaction diagram
benzylamine + H2O + ferricyanide
benzaldehyde + NH3 + reduced ferricyanide
show the reaction diagram
-
-
-
-
?
butylamine + acceptor + H2O
butanal + NH3 + reduced acceptor
show the reaction diagram
dithionite + amicyanin + H2O
?
show the reaction diagram
-
two-electron-reduced MADH is obtained by exposing the enzyme either to a 3fold molar excess of methylamine or to 2 mM dithionite
-
-
?
ethylamine + acceptor + H2O
acetaldehyde + NH3 + reduced acceptor
show the reaction diagram
histamine + acceptor + H2O
? + NH3 + reduced acceptor
show the reaction diagram
-
-
-
-
?
methylamine + acceptor + H2O
formaldehyde + NH3 + reduced acceptor
show the reaction diagram
methylamine + acceptor + H2O
methanal + NH3 + reduced acceptor
show the reaction diagram
methylamine + amicyanin + H2O
formaldehyde + NH3 + reduced amicyanin
show the reaction diagram
-
-
-
-
?
methylamine + amicyanin + H2O
formaldehyde + reduced amicyanin + NH3
show the reaction diagram
methylamine + H2O + 2 amicyanin
formaldehyde + NH3 + 2 reduced amicyanin
show the reaction diagram
methylamine + H2O + amicyanin
formaldehyde + ammonia + reduced amicyanin
show the reaction diagram
methylamine + H2O + amicyanin
formaldehyde + NH3 + reduced amicyanin
show the reaction diagram
-
-
-
?
n-butylamine + H2O + ferricyanide
butanal + NH3 + reduced ferricyanide
show the reaction diagram
-
-
-
-
?
n-hexylamine + acceptor + H2O
hexanal + NH3 + reduced acceptor
show the reaction diagram
n-nonylamine + acceptor + H2O
nonanal + NH3 + reduced acceptor
show the reaction diagram
-
-
-
-
?
n-pentylamine + acceptor + H2O
pentanal + NH3 + reduced acceptor
show the reaction diagram
-
-
-
-
?
phenylethylamine + acceptor + H2O
phenylacetaldehyde + NH3 + reduced acceptor
show the reaction diagram
propylamine + acceptor + H2O
propionaldehyde + NH3 + reduced acceptor
show the reaction diagram
RCH2NH2 + acceptor + H2O
RCHO + NH3 + reduced acceptor
show the reaction diagram
tryptamine + acceptor + H2O
?
show the reaction diagram
-
-
-
-
?
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
2-phenylethylamine + 2 H2O + 2 acceptor
2-phenylacetic acid + NH3 + 2 reduced acceptor
show the reaction diagram
-
primary amine
-
-
?
methylamine + amicyanin + H2O
formaldehyde + reduced amicyanin + NH3
show the reaction diagram
-
amicyanin is the in vivo electron acceptor
-
-
?
methylamine + H2O + 2 amicyanin
formaldehyde + NH3 + 2 reduced amicyanin
show the reaction diagram
methylamine + H2O + amicyanin
formaldehyde + NH3 + reduced amicyanin
show the reaction diagram
Q51658
-
-
-
?
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
cysteine tryptophylquinone
heme c
pyrroloquinoline quinone
-
covalently bound
quinoid cofactor
-
alpha subunit contains unknown quinoid cofactor
-
quinone
-
contains a quinone similar to but not identical with the prosthetic group of EC 1.1.99.8
tryptophan tryptophylquinone
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Fe
-
enzyme contains two heme groups
KCl
-
the rate of transfer of the first electron from methylamine-reduced MADH to amicyanin is increased by monovalent cations
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
8-hydroxyquinoline
-
slight
amicyanin mutant M98K
-
mutant acts as a competitive inhibitor in the reaction of native amicyanin with methylamine dehydrogenase indicating that the M98K mutation has not affected the affinity for its natural electron donor. The crystal structure of M98K amicyanin reveals an overall structure very similar to native amicyanin but the type I binding site is occupied by zinc instead of copper
-
Borohydride
-
-
Cuprizone
cyclopropylamine
-
mechanism-based inhibitor. The resulting inactivation is accompanied by the formation of a covalent cross-link between the alpha and beta subunits of the enzyme. No cross-linking is seen with mutant enzymes alphaF55A or alphaF55I mutant enzymes. With mutant enzyme alphaF55E cross-linking of subunits is observed
hydroxylamine
iodoacetate
-
-
Isoniazid
n-Butyraldehyde
-
-
N-ethylmaleimide
-
-
Neocuproine
-
slight
p-chloromercuribenzoate
p-Nitrophenylhydrazine
-
-
phenylhydrazine
Quinacrine
Quinine
-
slight
Semicarbazide
additional information
-
immobilized enzyme: little change in sensitivity to inhibition
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
benzylamine
-
activates sQH-AmDH
Dithionite
-
rapidly activates sQH-AmDH, activation process involves a reduction process
dithiothreitol
-
rapidly activates sQH-AmDH, activation process involves a reduction process
MauG
-
n-butylamine
-
activates sQH-AmDH
additional information
-
the gene which encodes MauG is located in the methylamine utilization (mau) gene cluster of several gram negative bacteria. The mau cluster contains the two structural genes for MADH as well as accessory proteins that are required for MADH biogenesis
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.003
1,12-diaminododecane
-
-
0.021 - 0.72
1,6-diaminohexane
0.007 - 0.38
1,7-Diaminoheptane
0.004 - 2.5
1-aminopentane
0.033
12-aminododecanoic acid
-
-
0.12
2,6-dichloroindophenol
-
-
0.007 - 0.87
Butylamine
0.042
cytochrome c-550
-
-
0.019 - 9.2
ethylamine
0.78
K3Fe(CN)6
-
-
0.004 - 22.4
methylamine
0.014
phenazine ethosulfate
-
-
0.006 - 1.3
Propylamine
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
3.4 - 43
1,6-diaminohexane
3.4 - 32
1,7-Diaminoheptane
3.4 - 20
1-aminopentane
1.5
2,6-dichloroindophenol
-
-
3.1
2-Phenylethylamine
-
pH 7.5, 30°C
0.77 - 74
amicyanin
-
3.8 - 22
benzylamine
4.2 - 34
Butylamine
2.3
cytochrome c-550
-
-
4.5 - 24
ethylamine
15
K3Fe(CN)6
-
-
0.14 - 77
methylamine
7.1
phenazine ethosulfate
-
-
26
phenethylamine
-
-
3.1 - 27
Propylamine
additional information
additional information
-
turnover numbers for deuterated substrates
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
-
heme 2 does not show any enzymatic activity for amine oxidation. Heme 2 is slowly activated in 10-30 h during incubation with n-butylamine. Enzyme is faster activated with benzylamine; sQH-AmDH is not electrochemically activated by direct electrolytic reduction with a column electrode at -0.5 V, but it is electrochemically activated by mediated electrolytic reduction with a column electrode
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7
-
1,12-diaminododecane
7.4
-
methylamine
9
-
putrescine
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
-
-
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
40
-
1,12-diaminododecane
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
8486
-
small subunit, MALDI-TOF mass spectrometry
8579
-
calculated gamma-subunit
8597
-
1 * 53917 + 1 * 39234 + 1 * 8597, calculated from amino acid sequence
12000
-
two bands appear in an SDS-PAGE: 12 kDa and 42 kDa
13960
-
L subunit, MALDI
13970
-
L subunit, calculated from sequence
14000
-
2 * 14000 + 2 * 41000, X-ray crystallography
14200
-
SDS-PAGE, beta subunit
38500
Mycobacterium convolutum
-
gel filtration
39000
-
1 * 60000 + 1 * 39000, SDS-PAGE
39234
-
1 * 53917 + 1 * 39234 + 1 * 8597, calculated from amino acid sequence
39360
-
calculated for beta-subunit, containing a 26 aa sequence which seems to correspond to a signal peptide that might be also involved in the correct translocation from the bacterial cytoplasm to the periplasmic space.
41000
-
2 * 14000 + 2 * 41000, X-ray crystallography
41160
-
H subunit, calculated from sequence
41170
-
H subunit, MALDI
43300
-
SDS-PAGE, alpha subunit
47000
-
1 * 47000, SDS-PAGE
53917
-
1 * 53917 + 1 * 39234 + 1 * 8597, calculated from amino acid sequence
54230
-
calculated for alpha-subunit, existence in this protein of two consensus sequences (CXXCH) identifying as binding pockets for the two haem groups
56000
-
gel filtration
58000
-
1 * 58000 + 1 * 42000, SDS-PAGE
60000
-
1 * 60000 + 1 * 39000, SDS-PAGE
95300
-
sedimentation equilibrium
100000
101700
-
calculated from amino acid sequence
112000
-
gel filtration
119000
133000
-
ultracentrifugation
138000
-
complex of methylamine dehydrogenase and amicyanin, gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
heterotetramer
heterotrimer
monomer
tetramer
trimer
-
alpha,beta,gamma, X-ray crystallography
additional information
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
proteolytic modification
additional information
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
one week in 19% PEG4000, 70 mM acetate buffer, pH 4.1
-
as MADH/amicyanin binary complex
-
crystals are grown in presence of 100 mM sodium citrate, pH 5.6, 18% PEG 4000 and 21% t-butyl alcohol. Complex of enzyme with the inhibitor phenylhydrazine determined at 1.7 A resolution
-
in complex with electron transfer protein amicyanin and with amicyanin mutant P52G. Model of electron transfer reaction between enzyme and amicyanin
-
macroseeding using a 9-to-1 mixture of monobasic sodium (3 M) and dibasic potassium (3 M) phosphate solutions as precipitant
-
MauG in complex with pre-methylamine dehydrogenase, hanging drop vapor diffusion method, using 23-25% (w/v) PEG 8000, 0.1 M sodium acetate, 0.1 M MES pH 6.4, at 20°C
-
MauG in complex with preMADH, X-ray diffraction structure determination and analysis at 2.1 resolution
-
MauG-pre-enzyme complex, hanging drop vapor diffusion method, using 0.1 M sodium acetate, 0.1 M MES pH 6.4, 22-26% PEG 8000
-
molecular dynamics simulations of the complex of redox proteins methylamine dehydrogenase and amicyanin to generate configurations over a duration of 40 ns in conjunction with an electron trnasfer pathway analysis. In the wild-type complex, the most frequently occurring molecular configurations afford superior electronic coupling due to the consistent presence of a water molecule hydrogen-bonded between the donor and acceptor sites. The water bridge function of nearby solvent-organizing residues by limiting the exchange of water molecules between the sterically constrained electron transfer region and the more turbulent surrounding bulk. When the water bridge is affected by a mutation, bulk solvent molecules disrupt it, resulting in reduced electronic coupling
-
preMADH complexed with MauG, X-ray diffraction structure determination and analysis at 2.1 A resolution
-
purified preenzyme pre-MADH in complex with activator mutant Q103N MauG, X-ray diffraction structure determination and analysis
-
sitting drop method, crystal structure of alphaF55A in complex with its electron acceptors, amicyanin and cytochrome c-551i. Little difference in the overal structure is seen, relative to the native complex. There are significant changes in the solvent content of the active site and substrate channel. Crystal structure of alphaF55A with phenylhydrazine covalently bound to tryptophan tryptophylquinone in the active site
-
MADH-amicyanin binary complex, hanging drop vapour diffusion method, in 28-29.5% PEG8000, 0.2 M Li2SO4, and 0.1 M phosphate (pH 6.5); the crystal structure of the complex of MADH and amicyanin is determined to 2.5 A using the hanging-drop method. Enzyme is a heterotetramer consisting of two heavy chains and two light chains. The heavy chain of MADH folds into a characteristic, seven-blade beta-propeller domain and contains an N-terminal extension (residues 1-80) that wraps around the neighboring light chain, fixing it to the tetrameric enzyme. The light subunit consists mainly of loop regions with only four beta-strands, stabilized by a total of six disulfide bridges, containing the active site of the enzyme, a tryptophan tryptophylquinone moiety formed by Trp57 covalently linked to Trp108
-
hanging drop vapour diffusion method with 18% (w/v) polyethylene glycol 2000 monomethylether and 50 mM NiCl2
-
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
2.6 - 10.6
-
75 min
396574
6 - 11
-
2 weeks, room temperature
396571
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
50
-
10 min
65
-
3 min, 97% loss of activity
80
-
15 min, stable, inactivated above
84
-
30 min, 40% loss of activity (immobilized enzyme), about 85% loss of activity (soluble enzyme)
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
dialysis against diethyldithiocarbamate, stable
-
freezing and thawing, stable
-
immobilized enzyme
-
no difference in temperature-stability and pH-stability at 1 mg protein/ml and 0.0005 mg/ml
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-15°C, 1 mg/ml protein concentration
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
; Superdex 75 gel filtration
-
DEAE column chromatography; using a DEAE column
-
enzyme is isolated to near purity by a sequence of hydroxyapatite and anion exchange chromatography
-
HiLoad Superdex 200 gel filtration
-
ion-exchange chromatography with DEAE-Toyopearl resin
-
nickel-affinity column chromatography
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in Escherichia coli; expressed in Escherichia coli BL21 cells
-
expressed in Rhodobacter sphaeroides
-
Expression in Escherichia coli, the production of knock out-mutants unable to catabolize 2-phenylethylamine is carried out by mutagenesis.
-
genes qhpA, qhpB, and qhpC encoding the alpha, beta, and gamma subunits of QHNDH, respectively. The structural genes encoding the three QHNDH subunits constitute an operon harboring six apparent open reading frames (ORFs) that are transcribed in a coordinated manner upon addition of amines to the culture medium. qhpADCBEF genes constitute a hexacistronic operon. DNA and amino acid sequence determination and analysis, and reverse transcription PCR expression analysis. Regulation of qhp genes, overview
-
heterologous expression of cytochrome c-550 in Escherichia coli
-
heterologous expression of mutated alpha subunit in Rhodobacter sphaeroides
-
MADH is a heterotetramer consisting of two alpha subunits and two beta subunits which are encoded by mauB and mauA, respectively
-
PreMADH can be generated by expression of recombinant MADH in the background of a mauG deletion
-
recombinant expression of pre-MADH in Rhodobacter sphaeroides
-
the methylamine utilization (mau) gene cluster contains 11genes, two of which encode the 42.5 kDa alpha-(mauB) and the 14.2 kDa beta-subunits (mauA) of MADH, recombinant co-overexpression of genes mauAB in Rhodobacter sphaeroides in the presence of mauDEFG, the four genes required for MADH maturation results in an alpha2beta2 MADH protein that has no catalytic activity, because the protein contains all six beta-subunit disulfides, but has a partially synthesized TTQ cofactor with only a single -OH group added to the indole of betaTrp57 (betaTrp57-OH)
-
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
an AraC family transcriptional regulator, ancoded by gene qhpR, activates expression of the qhp operon in response to the addition of n-butylamine to the culture medium
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
alphaF55A
alphaF55I
betaD32N
-
preparation contains a major species with six disulfides but no oxygen incorporated into betaTrp57 and a minor species with both oxygens incorporated, which is active. 1000fold increase in KM-value for methylamine
betaD76N
-
mutant enzyme is completely inactive
betaI107N
betaI107V
F55A
-
mutation of the alpha subunit
F55E
-
mutation of the alpha subunit
T122A
-
the presence of Thr122 has a deleterious effect on the proton transfer step that is proposed to determine the rate of the reaction, the substitution of Thr122 by Ala does not significantly modify the preference of the proton by atom OD2 of Asp76
K14E
-
mutation of cytochrome c-550
K14Q
-
mutation of cytochrome c-550
additional information
-
generation of of the gene disrupted mutant strains PdDELTAqhpF, PdDELTAqhpG, and PdDELTAqhpR
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
analysis
-
immobilized enzyme used as histamine biosensor
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