Biosynthesis of vitamin B12. Discovery of the enzymes for oxidative ring contraction and insertion of the fourth methyl group

FEBS Lett. 1993 Sep 27;331(1-2):105-8. doi: 10.1016/0014-5793(93)80306-f.

Abstract

In the vitamin B12 biosynthetic pathway the enzymes responsible for the conversion of precorrin-3 to precorrin-4 have been identified as the gene products of cobG and cobJ from Pseudomonas denitrificans. CobG catalyzes the oxidation of precorrin-3 to precorrin-3x (a hydroxy lactone) whereas CobJ is a SAM-dependent C-17 methyl transferase and is necessary for ring contraction. A mechanism for ring contraction is proposed.

Publication types

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

MeSH terms

  • Bacterial Proteins*
  • Base Sequence
  • DNA, Single-Stranded
  • Methylation
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Oxygenases / genetics
  • Oxygenases / metabolism*
  • Pseudomonas / enzymology
  • S-Adenosylmethionine / metabolism
  • Uroporphyrins / biosynthesis
  • Vitamin B 12 / biosynthesis*

Substances

  • Bacterial Proteins
  • DNA, Single-Stranded
  • Uroporphyrins
  • precorrin 3
  • S-Adenosylmethionine
  • Oxygenases
  • CobG protein, Pseudomonas denitrificans
  • CobJ protein, Pseudomonas denitrificans
  • Methyltransferases
  • Vitamin B 12