Information on EC 1.12.98.2 - 5,10-methenyltetrahydromethanopterin hydrogenase

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The expected taxonomic range for this enzyme is: Euryarchaeota

EC NUMBER
COMMENTARY hide
1.12.98.2
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RECOMMENDED NAME
GeneOntology No.
5,10-methenyltetrahydromethanopterin hydrogenase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
H2 + 5,10-methenyltetrahydromethanopterin = H+ + 5,10-methylenetetrahydromethanopterin
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oxidation
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-
-
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redox reaction
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-
-
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reduction
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Metabolic pathways
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Methane metabolism
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methanogenesis from CO2
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methanogenesis from H2 and CO2
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Microbial metabolism in diverse environments
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reductive acetyl coenzyme A pathway II (autotrophic methanogens)
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SYSTEMATIC NAME
IUBMB Comments
hydrogen:5,10-methenyltetrahydromethanopterin oxidoreductase
Does not catalyse the reduction of artificial dyes. Does not by itself catalyse a H2/H+ exchange reaction. Does not contain nickel or iron-sulfur clusters.
CAS REGISTRY NUMBER
COMMENTARY hide
100357-01-5
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ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
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SwissProt
Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
Methanothermobacter thermautotrophicum
Methanothermobacter thermautotrophicum Marburg
strain Marburg
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-
Manually annotated by BRENDA team
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SwissProt
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
5,10-methenyltetrahydromethanopterin + H2
5,10-methylenetetrahydromethanopterin + H+
show the reaction diagram
H+ + 5,10-methylenetetrahydromethanopterin
H2 + 5,10-methenyltetrahydromethanopterin
show the reaction diagram
N5,N10-methylenetetrahydromethanopterin + H+
N5,N10-methenyltetrahydromethanopterin + H2
show the reaction diagram
additional information
?
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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
5,10-methenyltetrahydromethanopterin + H2
5,10-methylenetetrahydromethanopterin + H+
show the reaction diagram
additional information
?
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COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
additional information
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
KCl
-
the enzyme requires the presence of salts, 50% of maximal activity is reached at 100 mM potassium phosphate, KCl or NaCl
NaCl
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the enzyme requires the presence of salts, 50% of maximal activity is reached at 100 mM potassium phosphate, KCl or NaCl
Nickel
Methanothermobacter thermautotrophicum
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contains less than 0.1 mol Ni per mol of enzyme
potassium phosphate
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the enzyme requires the presence of salts, 50% of maximal activity is reached at 100 mM potassium phosphate, KCl or NaCl
Zn2+
the zinc content varies from preparation to preparation between 0.5-4 mol zinc/mol enzyme
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
cyanide
1 mM, 50% inhibition
H2
Methanothermobacter thermautotrophicum
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inhibits formation of N5,N10-methenyltetrahydromethanopterin
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.05 - 0.07
5,10-methenyltetrahydromethanopterin
0.02 - 0.04
5,10-methylenetetrahydromethanopterin
0.002
H+
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pH 5.7
0.85
N5,N10-methenyltetrahydromethanopterin
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0.02 - 0.06
N5,N10-methylenetetrahydromethanopterin
additional information
H2
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
975
5,10-methenyltetrahydromethanopterin
Methanothermobacter marburgensis
P32440
pH 7.5, 60°C
1462
5,10-methylenetetrahydromethanopterin
Methanothermobacter marburgensis
P32440
pH 6.5, 60°C
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.1 - 0.2
CN-
0.01
CO
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pH 6.0, 40°C, under N2
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
610
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purified enzyme, pH 6.0, 40°C, under N2
750
Methanothermobacter thermautotrophicum
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800
Methanothermobacter thermautotrophicum
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pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.5 - 7
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reaction rate increases hyperbolically with the proton concentration between pH 7 and pH 4.5
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
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-
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
40 - 65
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2.5-fold higher activity at 65°C than at 40°C
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
4.4
isoelectric focussing
PDB
SCOP
CATH
ORGANISM
UNIPROT
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)
Methanothermobacter marburgensis (strain DSM 2133 / 14651 / NBRC 100331 / OCM 82 / Marburg)
Methanothermobacter marburgensis (strain DSM 2133 / 14651 / NBRC 100331 / OCM 82 / Marburg)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
38000
the Hmd holoenzyme is comprised of a homodimer of 38 kDa subunits, 2 pyridone derivative cofactor molecules and 2 iron atoms
45000
Methanothermobacter thermautotrophicum
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gradient PAGE
170000
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gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
homodimer
monomer
tetramer
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
hanging-drop or sitting-drop, vapour diffusion method. Crystal structure of the Hmd apoenzyme from Methanocaldococcus jannaschii at 1.75 A resolution
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hanging-drop or sitting-drop, vapour diffusion method. Crystal structure of the Hmd apoenzyme from Methanocaldococcus jannaschii at 2.4 A resolution
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TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
60
30 min, 50% inactivation
90
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60 min, stable, enzyme in cell extract; rapid inactivation of purified enzyme
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
50% loss of activity after freezing and thawing
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enzyme and cofactor are light sensitive
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sensitive to UV-A/blue light, CO protects from inactivation
the rate of inactivation increases upon dilution and in the presence of O2 and decreases upon the addition of 5 mg/ml albumin
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OXIDATION STABILITY
ORGANISM
UNIPROT
LITERATURE
enzyme is rapidly inactivated upon exposure to oxygen
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658635
purified enzyme is very labile even under strictly anoxic conditions
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394696
rapidly inactivated in the presence of molecular oxygen. The rate of inactivation increases in the presence of dithiothreitol (2 mM) or of mercaptoethanol (5 mM)
727402
stable to O2
Methanothermobacter thermautotrophicum
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394691
the enzyme is much more sensitive towards inactivation by O2 than the enzyme from Methanothermobacter marburgensis
727402
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-20°C, under N2 gas phase, 20% loss of activity within 2 weeks
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4°C, pH 7.6, 50 mM Tris-HCl, 20% glycerol, under N2 gas phase, 50% loss of activity after 1 week
Methanothermobacter thermautotrophicum
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Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
all purification steps are performed in the dark
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Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in Escherichia coli
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