Tetrahydromethanopterin-dependent methanogenesis from non-physiological C1 donors in Methanobacterium thermoautotrophicum

J Bacteriol. 1985 Feb;161(2):696-701. doi: 10.1128/JB.161.2.696-701.1985.

Abstract

Methanogenesis from the non-physiological C1 donors thioproline, thiazolidine, hexamethylenetetramine, formaldehyde (HCHO), and HOCH2-S-coenzyme M (CoM) was catalyzed by cell extracts of Methanobacterium thermoautotrophicum under a hydrogen atmosphere. Tetrahydromethanopterin (H4MPT) and HS-CoM were required in the reaction mixture. The non-physiological compounds were found to be in chemical equilibrium with HCHO, which has been shown to react spontaneously with H4MPT to form methylene-H4MPT, an intermediate of the methanogenic pathway at the formaldehyde level of oxidation. Highfield (360 MHZ) 1H and 13C nuclear magnetic resonance studies performed on the interaction between HCHO and HS-CoM showed that these compounds are in equilibrium with HOCH2-S-CoM and that the equilibrium is pH dependent. When methanogenesis from the non-physiological donors was followed under a nitrogen atmosphere, the C1 moiety from each compound underwent a disproportionation, forming methenyl-H4MPT+ and methane. The compounds tested served as substrates for the enzymatic synthesis of methenyl-H4MPT+.

Publication types

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

MeSH terms

  • Carbon / metabolism
  • Euryarchaeota / metabolism*
  • Formaldehyde / metabolism
  • Hydrogen / metabolism
  • Magnetic Resonance Spectroscopy
  • Methane / metabolism*
  • Nitrogen / pharmacology
  • Pterins / metabolism*

Substances

  • Pterins
  • Formaldehyde
  • Carbon
  • Hydrogen
  • 5,6,7,8-tetrahydromethanopterin
  • Nitrogen
  • Methane