Identification and characterization of an operon in Salmonella typhimurium involved in thiamine biosynthesis

J Bacteriol. 1997 Aug;179(15):4894-900. doi: 10.1128/jb.179.15.4894-4900.1997.


Thiamine pyrophosphate (TPP) is synthesized de novo in Salmonella typhimurium and is a required cofactor for many enzymes in the cell. Five kinase activities have been implicated in TPP synthesis, which involves joining a 4-methyl-5-(beta-hydroxyethyl)thiazole (THZ) moiety and a 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) moiety. We report here identification of a 2-gene operon involved in thiamine biosynthesis and present evidence that the genes in this operon, thiMD, encode two previously identified kinases, THZ kinase and HMP phosphate (HMP-P) kinase, respectively. We further show that this operon belongs to the growing class of genes involved in TPP synthesis that are transcriptionally regulated by TPP. Our data are consistent with ThiM being a salvage enzyme and ThiD being a biosynthetic enzyme involved in TPP synthesis, as previously suggested.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • DNA, Bacterial
  • Gene Expression Regulation, Bacterial
  • Gene Expression Regulation, Enzymologic
  • Molecular Sequence Data
  • Molecular Structure
  • Mutagenesis
  • Mutation
  • Operon*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics*
  • Phosphotransferases (Phosphate Group Acceptor) / genetics*
  • Polymerase Chain Reaction
  • Pyrimidines / metabolism
  • Salmonella typhimurium / enzymology*
  • Salmonella typhimurium / genetics
  • Sequence Homology, Amino Acid
  • Thiamine / biosynthesis*
  • Thiamine Pyrophosphate


  • 4-amino-5-hydroxymethyl-2-methylpyrimidine
  • DNA, Bacterial
  • Pyrimidines
  • 4-methyl-5-(beta-hydroxyethyl)thiazole kinase
  • Phosphotransferases (Alcohol Group Acceptor)
  • 4-amino-5-(hydroxymethyl)-2-methylpyrimidine phosphate kinase
  • Phosphotransferases (Phosphate Group Acceptor)
  • Thiamine Pyrophosphate
  • Thiamine

Associated data

  • GENBANK/U87940