| Autor: |
Fyfe, Cameron D., Bernardo-García, Noelia, Fradale, Laura, Grimaldi, Stéphane, Guillot, Alain, Brewee, Clémence, Chavas, Leonard M. G., Legrand, Pierre, Benjdia, Alhosna, Berteau, Olivier |
| Zdroj: |
Nature; Feb2022, Vol. 602 Issue 7896, p336-342, 7p |
| Abstrakt: |
By catalysing the microbial formation of methane, methyl-coenzyme M reductase has a central role in the global levels of this greenhouse gas1,2. The activity of methyl-coenzyme M reductase is profoundly affected by several unique post-translational modifications3–6, such as a unique C-methylation reaction catalysed by methanogenesis marker protein 10 (Mmp10), a radical S-adenosyl-l-methionine (SAM) enzyme7,8. Here we report the spectroscopic investigation and atomic resolution structure of Mmp10 from Methanosarcina acetivorans, a unique B12 (cobalamin)-dependent radical SAM enzyme9. The structure of Mmp10 reveals a unique enzyme architecture with four metallic centres and critical structural features involved in the control of catalysis. In addition, the structure of the enzyme–substrate complex offers a glimpse into a B12-dependent radical SAM enzyme in a precatalytic state. By combining electron paramagnetic resonance spectroscopy, structural biology and biochemistry, our study illuminates the mechanism by which the emerging superfamily of B12-dependent radical SAM enzymes catalyse chemically challenging alkylation reactions and identifies distinctive active site rearrangements to provide a structural rationale for the dual use of the SAM cofactor for radical and nucleophilic chemistry.Structural and spectroscopic studies show how a B12-dependent radical SAM enzyme catalyses unique and challenging alkylation chemistry, including protein post-translational modification required for methane biosynthesis. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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