9C0Q
Carbon monoxide dehydrogenase (CODH) from Methanosarcina thermophila, specimen prepared on blot plunger
Summary for 9C0Q
| Entry DOI | 10.2210/pdb9c0q/pdb |
| Related | 9C0R 9C0S 9C0T |
| EMDB information | 45089 45090 45091 45092 |
| Descriptor | Acetyl-CoA decarbonylase/synthase complex subunit alpha 2, Acetyl-CoA decarbonylase/synthase complex subunit epsilon 2, IRON/SULFUR CLUSTER, ... (4 entities in total) |
| Functional Keywords | co-dehydrogenase, oxidoreductase |
| Biological source | Methanosarcina thermophila More |
| Total number of polymer chains | 4 |
| Total formula weight | 216168.60 |
| Authors | |
| Primary citation | 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 Cited by 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: 39361653DOI: 10.1073/pnas.2410995121 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.3 Å) |
Structure validation
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