Complete nucleotide sequence of Tn1721: gene organization and a novel gene product with features of a chemotaxis protein

Gene. 1992 Feb 1;111(1):11-20. doi: 10.1016/0378-1119(92)90597-i.


The complete 11,139-nucleotide sequence of transposon Tn1721 has been determined. It contains three 38-bp inverted repeats, and (in this order) a new orfI, a resolution site (res), genes encoding resolvase (tnpR), transposase (tnpA), tetracycline-resistance (TcR) repressor (tetR), TcR (tetA) and a truncated transposase gene (tnpA'). The modulator origin of Tn1721 from at least three separate sources is supported by the distinctive codon usages of orfI, tnpR/tnpA and tetR/tetA, and by sequence similarities with Tn501 (tnpR/tnpA) and RP1 (tetR/tetA). The ORFI-encoded 56-kDa polypeptide exhibits features of a methyl-accepting chemotaxis protein (MCP) with a conserved signal domain and a potential transmembrane domain; this polypeptide cross-reacts with anti-MCP antiserum. Like chemotaxis genes, orfI is transcribed from a sigma 28-like promoter. The overexpressed orfI gene product interferes with MCP-dependent chemotaxis suggesting that it completes for soluble transducer protein(s) in the cell. The potential selective advantage of this novel transposon-borne gene is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Biological Evolution
  • Blotting, Western
  • Chemotactic Factors / genetics*
  • DNA
  • DNA Transposable Elements*
  • Escherichia coli Proteins*
  • Membrane Proteins / genetics*
  • Methyl-Accepting Chemotaxis Proteins
  • Molecular Sequence Data
  • Open Reading Frames
  • Promoter Regions, Genetic
  • Restriction Mapping
  • Sequence Alignment
  • Signal Transduction / genetics
  • Transcription, Genetic


  • Bacterial Proteins
  • Chemotactic Factors
  • DNA Transposable Elements
  • Escherichia coli Proteins
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • DNA

Associated data

  • GENBANK/M64367
  • GENBANK/M64425
  • GENBANK/M64426
  • GENBANK/M64427
  • GENBANK/S39996
  • GENBANK/S40001
  • GENBANK/S40008
  • GENBANK/S40009
  • GENBANK/S40010
  • GENBANK/X61367