Genetic evidence for a novel thymidylate synthase in the halophilic archaeon Halobacterium salinarum and in Campylobacter jejuni

FEMS Microbiol Lett. 2002 Oct 29;216(1):105-9. doi: 10.1111/j.1574-6968.2002.tb11422.x.


A search of the complete genome sequence of the halophilic archaeon Halobacterium salinarum failed to identify a gene homologous to the thymidylate synthase (thyA) gene present in the closely related Haloferax volcanii. To understand the source of thymidine synthesis in Hbt. salinarum, a genomic library of Hbt. salinarum was constructed and used to complement a Hfx. volcanii thyA deletion mutation. The Hbt. salinarum ORF that complemented the thyA mutation shares sequence homology with ORFs found in numerous microorganisms that lack a thyA gene, including the recently discovered thyX of Helicobacter pylori. We also show that a homolog of the Hbt. salinarum ORF is present in Campylobacter jejuni and is able to complement an Escherichia coli thyA mutant under oxygen-limiting conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Campylobacter jejuni / enzymology*
  • Campylobacter jejuni / genetics
  • Escherichia coli / genetics
  • Escherichia coli / growth & development
  • Gene Deletion
  • Genes, Archaeal
  • Genes, Bacterial
  • Genetic Complementation Test
  • Genomic Library
  • Halobacterium salinarum / enzymology*
  • Halobacterium salinarum / genetics
  • Open Reading Frames
  • Spectrophotometry
  • Thymidylate Synthase / analysis
  • Thymidylate Synthase / genetics*
  • Transformation, Bacterial


  • Thymidylate Synthase