Discovering New Enzymes and Metabolic Pathways: Conversion of Succinate to Propionate by Escherichia Coli

Biochemistry. 2000 Apr 25;39(16):4622-9. doi: 10.1021/bi992888d.

Abstract

The Escherichia coli genome encodes seven paralogues of the crotonase (enoyl CoA hydratase) superfamily. Four of these have unknown or uncertain functions; their existence was unknown prior to the completion of the E. coli genome sequencing project. The gene encoding one of these, YgfG, is located in a four-gene operon that encodes homologues of methylmalonyl CoA mutases (Sbm) and acyl CoA transferases (YgfH) as well as a putative protein kinase (YgfD/ArgK). We have determined that YgfG is methylmalonyl CoA decarboxylase, YgfH is propionyl CoA:succinate CoA transferase, and Sbm is methylmalonyl CoA mutase. These reactions are sufficient to form a metabolic cycle by which E. coli can catalyze the decarboxylation of succinate to propionate, although the metabolic context of this cycle is unknown. The identification of YgfG as methylmalonyl CoA decarboxylase expands the range of reactions catalyzed by members of the crotonase superfamily.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Carboxy-Lyases / chemistry
  • Carboxy-Lyases / genetics
  • Carboxy-Lyases / metabolism*
  • Catalysis
  • Cloning, Molecular
  • Cobamides / metabolism
  • Coenzyme A-Transferases / chemistry
  • Coenzyme A-Transferases / genetics
  • Coenzyme A-Transferases / metabolism*
  • Enoyl-CoA Hydratase / chemistry
  • Enoyl-CoA Hydratase / genetics
  • Enoyl-CoA Hydratase / metabolism
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Genes, Bacterial / genetics
  • Genes, Bacterial / physiology
  • Genome, Bacterial
  • Kinetics
  • Methylmalonyl-CoA Decarboxylase
  • Methylmalonyl-CoA Mutase / chemistry
  • Methylmalonyl-CoA Mutase / genetics
  • Methylmalonyl-CoA Mutase / metabolism*
  • Molecular Sequence Data
  • Multigene Family / genetics
  • Operon / genetics
  • Operon / physiology
  • Propionates / metabolism*
  • Protein Kinases / chemistry
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Racemases and Epimerases / chemistry
  • Racemases and Epimerases / genetics
  • Racemases and Epimerases / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Succinic Acid / metabolism*

Substances

  • Cobamides
  • Propionates
  • Succinic Acid
  • Protein Kinases
  • Coenzyme A-Transferases
  • succinyl CoA propionate CoA-transferase
  • Carboxy-Lyases
  • Enoyl-CoA Hydratase
  • Racemases and Epimerases
  • methylmalonyl-coenzyme A racemase
  • Methylmalonyl-CoA Mutase
  • Methylmalonyl-CoA Decarboxylase
  • cobamamide
  • propionic acid

Associated data

  • GENBANK/AE000375