Structural Basis of Hydrogenotrophic Methanogenesis.
Annu Rev Microbiol
; 74: 713-733, 2020 09 08.
Article
em En
| MEDLINE
| ID: mdl-32692612
ABSTRACT
Most methanogenic archaea use the rudimentary hydrogenotrophic pathway-from CO2 and H2 to methane-as the terminal step of microbial biomass degradation in anoxic habitats. The barely exergonic process that just conserves sufficient energy for a modest lifestyle involves chemically challenging reactions catalyzed by complex enzyme machineries with unique metal-containing cofactors. The basic strategy of the methanogenic energy metabolism is to covalently bind C1 species to the C1 carriers methanofuran, tetrahydromethanopterin, and coenzyme M at different oxidation states. The four reduction reactions from CO2 to methane involve one molybdopterin-based two-electron reduction, two coenzyme F420-based hydride transfers, and one coenzyme F430-based radical process. For energy conservation, one ion-gradient-forming methyl transfer reaction is sufficient, albeit supported by a sophisticated energy-coupling process termed flavin-based electron bifurcation for driving the endergonic CO2 reduction and fixation. Here, we review the knowledge about the structure-based catalytic mechanism of each enzyme of hydrogenotrophic methanogenesis.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Archaea
/
Metabolismo Energético
/
Hidrogênio
/
Metano
/
Complexos Multienzimáticos
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article