KEGG   PATHWAY: map00680Help
Entry
map00680                    Pathway                                

Name
Methane metabolism
Description
Methane is metabolized principally by methanotrophs and methanogens in the global carbon cycle. Methanotrophs consume methane as the only source of carbon, while methanogens produce methane as a metabolic byproduct. Methylotrophs, which are microorganisms that can obtain energy for growth by oxidizing one-carbon compounds, such as methanol and methane, are situated between methanotrophs and methanogens. Methanogens can obtain energy for growth by converting a limited number of substrates to methane under anaerobic conditions. Three types of methanogenic pathways are known: CO2 to methane [MD:M00567], methanol to methane [MD:M00356], and acetate to methane [MD:M00357]. Methanogens use 2-mercaptoethanesulfonate (CoM; coenzyme M) as the terminal methyl carrier in methanogenesis and have four enzymes for CoM biosynthesis [MD:M00358]. Coenzyme B-Coenzyme M heterodisulfide reductase (Hdr), requiring for the final reaction steps of methanogenic pathway, is divided into two types: cytoplasmic HdrABC in most methanogens and membrane-bound HdrED in Methanosarcina species. In methanotrophs and methyltrophs methane is oxidized to form formaldehyde, which is at the diverging point for further oxidation to CO2 for energy source and assimilation for biosynthesis. There are three pathways that convert formaldehyde to C2 or C3 compounds: serine pathway [MD:M00346], ribulose monophosphate pathway [MD:M00345], and xylulose monophosphate pathway [MD:M00344]. The first two pathways are found in prokaryotes and the third is found in yeast. As a special case of methylotrophs, various amines can be used as carbon sources in trimethylamine metabolism [MD:M00563].
Class
Metabolism; Energy metabolism
BRITE hierarchy
Pathway map
map00680  Methane metabolism
map00680

Ortholog table
Module
M00174  Methane oxidation, methanotroph, methane => formaldehyde [PATH:map00680]
M00344  Formaldehyde assimilation, xylulose monophosphate pathway [PATH:map00680]
M00345  Formaldehyde assimilation, ribulose monophosphate pathway [PATH:map00680]
M00346  Formaldehyde assimilation, serine pathway [PATH:map00680]
M00356  Methanogenesis, methanol => methane [PATH:map00680]
M00357  Methanogenesis, acetate => methane [PATH:map00680]
M00358  Coenzyme M biosynthesis [PATH:map00680]
M00378  F420 biosynthesis [PATH:map00680]
M00422  Acetyl-CoA pathway, CO2 => acetyl-CoA [PATH:map00680]
M00563  Methanogenesis, methylamine/dimethylamine/trimethylamine => methane [PATH:map00680]
M00567  Methanogenesis, CO2 => methane [PATH:map00680]
M00608  2-Oxocarboxylic acid chain extension, 2-oxoglutarate => 2-oxoadipate => 2-oxopimelate => 2-oxosuberate [PATH:map00680]
Disease
H00203  Acatalasemia
Other DBs
GO: 0015947
Reference
  Authors
Graham DE, Xu H, White RH
  Title
Identification of coenzyme M biosynthetic phosphosulfolactate synthase: a new family of sulfonate-biosynthesizing enzymes.
  Journal
J Biol Chem 277:13421-9 (2002)
DOI:10.1074/jbc.M201011200
Reference
  Authors
Deppenmeier U
  Title
The membrane-bound electron transport system of Methanosarcina species.
  Journal
J Bioenerg Biomembr 36:55-64 (2004)
DOI:10.1023/B:JOBB.0000019598.64642.97
Reference
  Authors
Hallam SJ, Putnam N, Preston CM, Detter JC, Rokhsar D, Richardson PM, DeLong EF
  Title
Reverse methanogenesis: testing the hypothesis with environmental genomics.
  Journal
Science 305:1457-62 (2004)
DOI:10.1126/science.1100025
Reference
  Authors
Welander PV, Metcalf WW
  Title
Loss of the mtr operon in Methanosarcina blocks growth on methanol, but not methanogenesis, and reveals an unknown methanogenic pathway.
  Journal
Proc Natl Acad Sci U S A 102:10664-9 (2005)
DOI:10.1073/pnas.0502623102
Reference
  Authors
Yurimoto H, Kato N, Sakai Y
  Title
Assimilation, dissimilation, and detoxification of formaldehyde, a central metabolic intermediate of methylotrophic metabolism.
  Journal
Chem Rec 5:367-75 (2005)
DOI:10.1002/tcr.20056
Reference
  Authors
Fricke WF, Seedorf H, Henne A, Kruer M, Liesegang H, Hedderich R, Gottschalk G, Thauer RK.
  Title
The genome sequence of Methanosphaera stadtmanae reveals why this human intestinal archaeon is restricted to methanol and H2 for methane formation and ATP synthesis.
  Journal
J Bacteriol 188:642-58 (2006)
DOI:10.1128/JB.188.2.642-658.2006
Reference
  Authors
Kato N, Yurimoto H, Thauer RK
  Title
The physiological role of the ribulose monophosphate pathway in bacteria and archaea.
  Journal
Biosci Biotechnol Biochem 70:10-21 (2006)
DOI:10.1271/bbb.70.10
Reference
  Authors
Thauer RK, Kaster AK, Seedorf H, Buckel W, Hedderich R
  Title
Methanogenic archaea: ecologically relevant differences in energy conservation.
  Journal
Nat Rev Microbiol 6:579-91 (2008)
DOI:10.1038/nrmicro1931
Reference
  Authors
Liffourrena AS, Salvano MA, Lucchesi GI
  Title
Pseudomonas putida A ATCC 12633 oxidizes trimethylamine aerobically via two different pathways.
  Journal
Arch Microbiol 192:471-6 (2010)
DOI:10.1007/s00203-010-0577-5
KO pathway
ko00680   

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