On the role of N‐7‐mercaptoheptanoyl‐O‐phospho‐L‐threonine (component B) in the enzymatic reduction of methyl‐coenzyme M to methane
- 17 August 1987
- journal article
- Published by Wiley in FEBS Letters
- Vol. 220 (2) , 358-362
- https://doi.org/10.1016/0014-5793(87)80846-3
Abstract
The reduction of methyl-coenzyme M (CH3SCoM) to methane in methanogenic bacteria is dependent on component B (N-7-mercaptoheptanoyl-O-phospho-L-threonine, HSHTP). We report here that S-methyl-component B (N-7-(methylthio)heptanoyl-O-phospho-L-threonine, CH3SHTP) can substitute for neither CH3SCoM nor HSHTP in the methyl-CoM reductase reaction. Rather, CH3SHTP proved to be an inhibitor competitive with HSHTP (apparent Ki = 6 microM) and noncompetitive with CH3SCoM. These results make it very unlikely that HSHTP functions as a methyl group carrier. A role for HSHTP as direct electron donor for CH3SCoM reduction to CH4 is proposed.Keywords
This publication has 24 references indexed in Scilit:
- The L‐form of N‐7‐mercaptoheptanoyl‐O‐phosphothreonine is the enantiomer active as component B in methyl‐CoM reduction to methaneFEBS Letters, 1987
- 7‐Mercaptoheptanoylthreonine phosphate functions as component B in ATP‐independent methane formation from methyl‐CoM with reduced cobalamin as electron donorFEBS Letters, 1987
- Component C of the methylcoenzyme M methylreductase system contains bound 7-mercaptoheptanoylthreonine phosphate (HS-HTP)Biochemical and Biophysical Research Communications, 1986
- Cobamide‐containing membrane protein complex in MethanobacteriumFEBS Letters, 1986
- Coenzyme F430 from methanogenic bacteria: reversible one-electron reduction of F430 pentamethyl ester to the nickel(I) formJournal of the Chemical Society, Chemical Communications, 1986
- Evidence for a chemiosmotic mechanism of ATP synthesis in methanogenic bacteriaTrends in Biochemical Sciences, 1985
- Zur Kenntnis des Faktors F430 aus methanogenen Bakterien: Absolute KonfigurationHelvetica Chimica Acta, 1985
- Nickel tetrapyrrole cofactor F430: comparison of the forms bound to methyl S-coenzyme M reductase and protein free in cells of Methanobacterium thermoautotrophicum .DELTA.HBiochemistry, 1984
- Zur Kenntnis des Faktors F430 aus methanogenen Bakterien: Struktur des proteinfreien FaktorsHelvetica Chimica Acta, 1984
- Presence of coenzyme M derivatives in the prosthetic group (coenzyme MF430) of methylcoenzyme M reductase from Methanobacterium thermoautotrophicumBiochemical and Biophysical Research Communications, 1982