Structural highlights
5a8r is a 12 chain structure with sequence from Methanothermobacter marburgensis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Method: | X-ray diffraction, Resolution 2.15Å |
| Ligands: | , , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
MCRY_METTM Component of the methyl-coenzyme M reductase (MCR) I that catalyzes the reductive cleavage of methyl-coenzyme M (CoM-S-CH3 or 2-(methylthio)ethanesulfonate) using coenzyme B (CoB or 7-mercaptoheptanoylthreonine phosphate) as reductant which results in the production of methane and the mixed heterodisulfide of CoB and CoM (CoM-S-S-CoB). This is the final step in methanogenesis.[1]
Publication Abstract from PubMed
All methanogenic and methanotrophic archaea known to date contain methyl-coenzyme M reductase (MCR) that catalyzes the reversible reduction of methyl-coenzyme M to methane. This enzyme contains the nickel porphinoid F430 as a prosthetic group and, highly conserved, a thioglycine and four methylated amino acid residues near the active site. We describe herein the presence of a novel post-translationally modified amino acid, didehydroaspartate, adjacent to the thioglycine as revealed by mass spectrometry and high-resolution X-ray crystallography. Upon chemical reduction, the didehydroaspartate residue was converted into aspartate. Didehydroaspartate was found in MCR I and II from Methanothermobacter marburgensis and in MCR of phylogenetically distantly related Methanosarcina barkeri but not in MCR I and II of Methanothermobacter wolfeii, which indicates that didehydroaspartate is dispensable but might have a role in fine-tuning the active site to increase the catalytic efficiency.
Didehydroaspartate Modification in Methyl-Coenzyme M Reductase Catalyzing Methane Formation.,Wagner T, Kahnt J, Ermler U, Shima S Angew Chem Int Ed Engl. 2016 Jul 28. doi: 10.1002/anie.201603882. PMID:27467699[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Rospert S, Linder D, Ellermann J, Thauer RK. Two genetically distinct methyl-coenzyme M reductases in Methanobacterium thermoautotrophicum strain Marburg and delta H. Eur J Biochem. 1990 Dec 27;194(3):871-7. PMID:2269306 doi:10.1111/j.1432-1033.1990.tb19481.x
- ↑ Wagner T, Kahnt J, Ermler U, Shima S. Didehydroaspartate Modification in Methyl-Coenzyme M Reductase Catalyzing Methane Formation. Angew Chem Int Ed Engl. 2016 Jul 28. doi: 10.1002/anie.201603882. PMID:27467699 doi:http://dx.doi.org/10.1002/anie.201603882
