Structure of component B (7-mercaptoheptanoylthreonine phosphate) of the methylcoenzyme M methylreductase system of Methanobacterium thermoautotrophicum

Proc Natl Acad Sci U S A. 1986 Jun;83(12):4238-42. doi: 10.1073/pnas.83.12.4238.

Abstract

Component B, the heat-stable low-molecular-weight cofactor required for methane production by dialyzed cell-free extracts of Methanobacterium thermoautotrophicum, has been purified to homogeneity and its structure assigned. Results of low-resolution fast-atom-bombardment and field-desorption mass spectrometry indicated a molecular weight of 419, and high-resolution fast-atom-bombardment mass spectrometry agreed with the molecular formula C13H26NO8PS2. Evidence from fast-atom-bombardment and field-desorption mass spectrometry and 360-MHz 1H NMR in deuterium oxide argued that the compound was isolated as a mixed disulfide with 2-mercaptoethanol; so the proposed elemental formula of the free acid, free thiol would be C11H22NO7PS (molecular weight, 343). The proposed structure for an active form of the coenzyme is 7-mercaptoheptanoylthreonine phosphate.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amides / isolation & purification
  • Euryarchaeota / enzymology*
  • Fatty Acids / isolation & purification
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Mesna / analysis
  • Mesna / metabolism
  • Oxidoreductases / analysis
  • Oxidoreductases / metabolism*
  • Phosphothreonine / analogs & derivatives*
  • Phosphothreonine / isolation & purification
  • Sulfhydryl Compounds / isolation & purification*
  • Threonine / analogs & derivatives*

Substances

  • Amides
  • Fatty Acids
  • Sulfhydryl Compounds
  • 7-mercaptoheptanoylthreonine phosphate
  • Phosphothreonine
  • Threonine
  • Oxidoreductases
  • methyl coenzyme M reductase
  • Mesna