Evolution of Multi-Gene Segments in the mutS-rpoS Intergenic Region of Salmonella Enterica Serovar Typhimurium LT2

Microbiology. 2002 Aug;148(Pt 8):2531-2540. doi: 10.1099/00221287-148-8-2531.


The nucleotide sequence of the 12.6 kb region between the mutS and rpoS genes of Salmonella enterica serovar Typhimurium LT2 (S. typhimurium) was compared to other enteric bacterial mutS-rpoS intergenic regions. The mutS-rpoS region is composed of three distinct segments, designated HK, O and S, as defined by sequence similarities to contiguous ORFs in other bacteria. Inverted chromosomal orientations of each of these segments are found between the mutS and rpoS genes in related ENTEROBACTERIACEAE: The HK segment is distantly related to a cluster of seven ORFs found in Haemophilus influenzae and a cluster of five ORFs found between the mutS and rpoS genes in Escherichia coli K-12. The O segment is related to the mutS-rpoS intergenic region found in E. coli O157:H7 and Shigella dysenteriae type 1. The third segment, S, is common to diverse Salmonella species, but is absent from E. coli. Despite the extensive collinearity and conservation of the overall genetic maps of S. typhimurium and E. coli K-12, the insertions, deletions and inversions in the mutS-rpoS region provide evidence that this region of the chromosome is an active site for horizontal gene transfer and rearrangement.

MeSH terms

  • Adenosine Triphosphatases / genetics*
  • Bacterial Proteins / genetics
  • Chromosome Deletion
  • Chromosome Inversion
  • Chromosomes, Bacterial
  • DNA, Intergenic / genetics*
  • DNA-Binding Proteins*
  • Escherichia coli Proteins / genetics*
  • Evolution, Molecular*
  • Gene Rearrangement
  • Genes, Bacterial*
  • Genome, Bacterial
  • Molecular Sequence Data
  • Multigene Family
  • MutS DNA Mismatch-Binding Protein
  • Nucleic Acid Hybridization
  • Open Reading Frames
  • Salmonella enterica / genetics*
  • Sigma Factor / genetics*


  • Bacterial Proteins
  • DNA, Intergenic
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Sigma Factor
  • sigma factor KatF protein, Bacteria
  • Adenosine Triphosphatases
  • MutS DNA Mismatch-Binding Protein
  • MutS protein, E coli

Associated data

  • GENBANK/AY050714