Identification, Sequences, and Expression of Treponema Pallidum Chemotaxis Genes

DNA Seq. 1997;7(5):267-84. doi: 10.3109/10425179709034046.

Abstract

Treponema pallidum, the agent of syphilis, is a pathogenic spirochete that has no known mechanisms of genetic exchange and cannot be continuously cultivated in vitro. A probe based on the nucleotide sequence of the T. pallidum cheA gene was used to screen a T. pallidum genomic DNA library. A treponemal DNA region containing four open reading frames (orfs) was identified. The proteins encoded by these orfs have significant homology with proteins involved in bacterial chemotaxis. The orfs have been designated cheA, cheW, cheX, and cheY. The cheA, cheW, and cheY genes were individually-cloned and expressed in vitro. The observed molecular mass of each protein correlated well with its predicted molecular mass. Reverse transcriptase-PCR data indicate that cheA through cheY are co-transcribed. The organization of these genes suggests that they comprise an operon. We hypothesize that the ability to sense and respond to nutrient gradients is important for the survival and dissemination of T. pallidum in vivo. The presence of a putative che operon strongly suggests that T. pallidum has the potential for a chemotactic response.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Chemotaxis / genetics*
  • Cloning, Molecular
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression Regulation, Bacterial* / genetics*
  • Genes, Bacterial
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Methyl-Accepting Chemotaxis Proteins
  • Molecular Sequence Data
  • Open Reading Frames / genetics
  • Polymerase Chain Reaction
  • Restriction Mapping
  • Sequence Analysis, DNA
  • Sequence Homology
  • Sequence Homology, Amino Acid
  • Treponema pallidum / chemistry
  • Treponema pallidum / genetics*
  • Treponema pallidum / physiology

Substances

  • Bacterial Proteins
  • CheX protein, Treponema pallidum
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • CheW protein, Bacteria

Associated data

  • GENBANK/A44130
  • GENBANK/K02175
  • GENBANK/P07363
  • GENBANK/P07365
  • GENBANK/P29072
  • GENBANK/U28962
  • GENBANK/U61498
  • GENBANK/U61851