The eutT gene of Salmonella enterica Encodes an oxygen-labile, metal-containing ATP:corrinoid adenosyltransferase enzyme

J Bacteriol. 2004 Sep;186(17):5708-14. doi: 10.1128/JB.186.17.5708-5714.2004.

Abstract

The eutT gene of Salmonella enterica was cloned and overexpressed, and the function of its product was established in vivo and in vitro. The EutT protein has an oxygen-labile, metal-containing ATP:co(I)rrinoid adenosyltransferase activity associated with it. Functional redundancy between EutT and the housekeeping ATP:co(I)rrinoid adenosyltransferase CobA enzyme was demonstrated through phenotypic analyses of mutant strains. Lack of CobA and EutT blocked ethanolamine utilization. EutT was necessary and sufficient for growth of an S. enterica cobA eutT strain on ethanolamine as a carbon and energy or nitrogen source. A eutT+ gene provided in trans corrected the adenosylcobalamin-dependent transcription of a eut-lacZ operon fusion in a cobA strain. Cell extracts enriched for EutT protein contained strong, readily detectable ATP:co(I)rrinoid adenosyltransferase activity. The activity was only detected in extracts maintained under anoxic conditions, with complete loss of activity upon exposure to air or treatment with the Fe2+ ion chelator bathophenanthroline. While the involvement of another metal ion cannot be ruled out, the observed sensitivity to air and bathophenanthroline suggests involvement of Fe2+. We propose that the EutT protein is a unique metal-containing ATP:co(I)rrinoid adenosyltransferase. It is unclear whether the metal ion plays a structural or catalytic role.

Publication types

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

MeSH terms

  • Alkyl and Aryl Transferases / genetics
  • Alkyl and Aryl Transferases / isolation & purification
  • Alkyl and Aryl Transferases / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism*
  • Cloning, Molecular
  • Cobamides / metabolism
  • Coenzymes / metabolism
  • Ethanolamine / metabolism
  • Gene Deletion
  • Genes, Bacterial*
  • Genes, Reporter / genetics
  • Genes, Reporter / physiology
  • Genetic Complementation Test
  • Iron / metabolism
  • Metals / metabolism
  • Mutagenesis, Insertional
  • Mutation
  • Phenanthrolines / metabolism
  • Salmonella enterica / enzymology*
  • Salmonella enterica / genetics
  • Transcription, Genetic
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism

Substances

  • Bacterial Proteins
  • Cobamides
  • Coenzymes
  • Metals
  • Phenanthrolines
  • bathophenanthroline
  • Ethanolamine
  • Iron
  • Alkyl and Aryl Transferases
  • ATP-corrinoid adenosyltransferase
  • beta-Galactosidase
  • cobamamide