Comparison of the Promoter Proximal Regions of the Toxin-Co-Regulated TCP Gene Cluster in Classical and El Tor Strains of Vibrio Cholerae O1

Gene. 1996 Apr 17;170(1):9-16. doi: 10.1016/0378-1119(95)00744-x.


A physical map has been constructed of the 5-kb XbaI fragment encoding the promoter proximal of region the tcp gene cluster encoding the toxin-coregulated pilus (TCP) of Vibrio cholerae. This fragment contains the major regulatory regions for TCP. Comparison of the nucleotide (nt) sequences from strains of the classical and El Tor biotypes demonstrates that the regions are essentially identical, with several notable exceptions. The intergenic regions, between tcpI and tcpP, and between tcpH and tcpA, show significant sequence divergence which may account for the biotype-related differences in TCP, since this is the location of the major promoter sequences. The C-terminal coding regions of the major pilin subunit, TcpA, also differ. Southern hybridization analyses suggest that the tcpA nt sequence is conserved within a biotype, and Western blot analysis suggests that the two forms of TcpA are antigenically different, but related. Besides tcpA, tcpB, tcpH and tcpI, the genes encoding two additional proteins, TcpP and TcpQ, but not previously defined, were also identified. TcpH and TcpI have been previously suggested to be regulatory proteins but homology data imply that TcpI is a methyl-accepting chemotaxis protein (MCP), as recently reported [Harkey et al., Infect. Immun. 62 (1994) 2669-2678], and TcpH is predicted to be a periplasmic or exported protein. TcpP is thought to be a trans-cytoplasmic membrane (CM) protein which may have a regulatory role.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Adhesion / genetics
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Proteins / genetics
  • Base Sequence
  • Fimbriae Proteins*
  • Fimbriae, Bacterial / metabolism*
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial*
  • Genes, Regulator
  • Lipoproteins
  • Molecular Sequence Data
  • Promoter Regions, Genetic*
  • Repressor Proteins / genetics
  • Sequence Homology
  • Species Specificity
  • Transcription Factors*
  • Vibrio cholerae / classification
  • Vibrio cholerae / genetics*
  • Vibrio cholerae / pathogenicity
  • Virulence / genetics


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Lipoproteins
  • Repressor Proteins
  • TCPP protein, Vibrio cholerae
  • TcpA protein, Vibrio cholerae
  • TcpB protein, Vibrio cholerae
  • TcpC protein, Vibrio cholerae
  • TcpH protein, Vibrio cholerae
  • TcpI protein, Vibrio cholerae
  • TcpQ protein, Vibrio cholerae
  • Transcription Factors
  • Fimbriae Proteins

Associated data

  • GENBANK/X74730