9C0R

Carbon monoxide dehydrogenase (CODH) from Methanosarcina thermophila, specimen prepared on chameleon plunger

9C0R の概要

• エントリーDOI: 10.2210/pdb9c0r/pdb
• 関連するPDBエントリー: 9C0Q 9C0S 9C0T
• EMDBエントリー: 45090
• 分子名称: Acetyl-CoA decarbonylase/synthase complex subunit alpha 2, Acetyl-CoA decarbonylase/synthase complex subunit epsilon 2, IRON/SULFUR CLUSTER, ... (5 entities in total)
• 機能のキーワード: co-dehydrogenase, oxidoreductase
• 由来する生物種: Methanosarcina thermophila; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 216168.60

構造登録者

Biester, A.,Drennan, C.L. (登録日: 2024-05-27, 公開日: 2024-10-16)

主引用文献

Biester, A.,Grahame, D.A.,Drennan, C.L.
Capturing a methanogenic carbon monoxide dehydrogenase/acetyl-CoA synthase complex via cryogenic electron microscopy.
Proc.Natl.Acad.Sci.USA, 121:e2410995121-e2410995121, 2024

PubMed Abstract: Approximately two-thirds of the estimated one-billion metric tons of methane produced annually by methanogens is derived from the cleavage of acetate. Acetate is broken down by a Ni-Fe-S-containing A-cluster within the enzyme acetyl-CoA synthase (ACS) to carbon monoxide (CO) and a methyl group (CH). The methyl group ultimately forms the greenhouse gas methane, whereas CO is converted to the greenhouse gas carbon dioxide (CO) by a Ni-Fe-S-containing C-cluster within the enzyme carbon monoxide dehydrogenase (CODH). Although structures have been solved of CODH/ACS from acetogens, which use these enzymes to make acetate from CO, no structure of a CODH/ACS from a methanogen has been reported. In this work, we use cryo-electron microscopy to reveal the structure of a methanogenic CODH and CODH/ACS from (CODH/ACS). We find that the N-terminal domain of acetogenic ACS, which is missing in all methanogens, is replaced by a domain of CODH. This CODH domain provides a channel for CO to travel between the two catalytic Ni-Fe-S clusters. It generates the binding surface for ACS and creates a remarkably similar CO alcove above the A-cluster using residues from CODH rather than ACS. Comparison of our CODH/ACS structure with our CODH structure reveals a molecular mechanism to restrict gas flow from the CO channel when ACS departs, preventing CO escape into the cell. Overall, these long-awaited structures of a methanogenic CODH/ACS reveal striking functional similarities to their acetogenic counterparts despite a substantial difference in domain organization.

PubMed: 39361653
DOI: 10.1073/pnas.2410995121

実験手法

ELECTRON MICROSCOPY (2.8 Å)