Re-citrate synthase from Clostridium kluyveri is phylogenetically related to homocitrate synthase and isopropylmalate synthase rather than to Si-citrate synthase

J Bacteriol. 2007 Jun;189(11):4299-304. doi: 10.1128/JB.00198-07. Epub 2007 Mar 30.

Abstract

The synthesis of citrate from acetyl-coenzyme A and oxaloacetate is catalyzed in most organisms by a Si-citrate synthase, which is Si-face stereospecific with respect to C-2 of oxaloacetate. However, in Clostridium kluyveri and some other strictly anaerobic bacteria, the reaction is catalyzed by a Re-citrate synthase, whose primary structure has remained elusive. We report here that Re-citrate synthase from C. kluyveri is the product of a gene predicted to encode isopropylmalate synthase. C. kluyveri is also shown to contain a gene for Si-citrate synthase, which explains why cell extracts of the organism always exhibit some Si-citrate synthase activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2-Isopropylmalate Synthase / genetics*
  • 2-Isopropylmalate Synthase / metabolism
  • Citrate (si)-Synthase / genetics*
  • Citrate (si)-Synthase / metabolism
  • Citrates / chemistry
  • Citrates / metabolism
  • Clostridium kluyveri / enzymology
  • Clostridium kluyveri / genetics*
  • Clostridium kluyveri / metabolism
  • Genome, Bacterial
  • Molecular Structure
  • Oxaloacetic Acid / chemistry
  • Oxaloacetic Acid / metabolism
  • Oxo-Acid-Lyases / genetics*
  • Oxo-Acid-Lyases / metabolism
  • Phylogeny*
  • Stereoisomerism

Substances

  • Citrates
  • Oxaloacetic Acid
  • Citrate (si)-Synthase
  • 2-Isopropylmalate Synthase
  • homocitrate synthase
  • Oxo-Acid-Lyases