Nucleotide sequence analysis and expression studies of a chloramphenicol-acetyltransferase-coding gene from...

The nucleotide sequence of a CmR determinant, located on the Clostridium perfringens plasmid pIP401, was determined and its gene product was identified as chloramphenicol acetyltransferase (CAT). The cat structural gene is preceded by transcription-initiation signals characteristic for Escherichia coli sigma 70 or Bacillus subtilis sigma 43 promoters. By promoter probing in the heterologous hosts the direction of transcription of the clostridial cat gene was analysed and the cat mRNA start point was determined in vitro using the RNA polymerases of E. coli and B. subtilis. Comparison of the amino acid sequences of C. perfringens CAT and other CAT proteins of Gram-positive and Gram-negative origin shows a remarkable degree of homology between the various enzymes.