| EC |
6.2.2.1 |
| Accepted name: |
thioglycine synthase |
| Reaction: |
ATP + sulfide + a [methyl-coenzyme M reductase]-glycine = ADP + phosphate + a [methyl-coenzyme M reductase]-thioglycine |
| Glossary: |
thioglycine = 2-aminoethanethioic O-acid |
| Other name(s): |
ycaO (gene name) (ambiguous) |
| Systematic name: |
[methyl-coenzyme M reductase]-glycine—sulfur ligase (thioglycine-forming) |
| Comments: |
Requires Mg2+. The enzyme is found in anaerobic methanogenic and methanotrophic archaea, where it modifies a glycine residue in EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase (methyl-CoM reductase). Upon binding to its substrate, an external source of sulfide attacks the target amide bond generating a tetrahedral intermediate. The amide oxyanion attacks the γ-phosphate of ATP, releasing ADP and forming a phosphorylated thiolate intermediate that collapses to form thioglycine and phosphate. In most organisms activity requires a second protein (TfuA) , which may allosterically activate this enzyme or assist in the delivery of sulfide to the substrate. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
| References: |
| 1. |
Nayak, D.D., Mahanta, N., Mitchell, D.A. and Metcalf, W.W. Post-translational thioamidation of methyl-coenzyme M reductase, a key enzyme in methanogenic and methanotrophic Archaea. Elife 6:e29218 (2017). [PMID: 28880150] |
| 2. |
Mahanta, N., Liu, A., Dong, S., Nair, S.K. and Mitchell, D.A. Enzymatic reconstitution of ribosomal peptide backbone thioamidation. Proc. Natl. Acad. Sci. USA 115 (2018) 3030–3035. [PMID: 29507203] |
| 3. |
Dong, S.H., Liu, A., Mahanta, N., Mitchell, D.A. and Nair, S.K. Mechanistic basis for ribosomal peptide backbone modifications. ACS Cent. Sci. 5 (2019) 842–851. [PMID: 31139720] |
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| [EC 6.2.2.1 created 2020] |
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