AN ISOLEUCYL-TRANSFER-RNA SYNTHETASE GENE FROM CAMPYLOBACTER-JEJUNI

A complete isoleucyl-tRNA synthetase gene (ileS) of Campylobacter jeju ni was isolated from a C. jejuni TGH9011 genomic DNA library construct ed in pBluescript. The complete coding sequence, flanking regions and transcription start point were determined. The deduced isoleucyl-tRNA synthetase (IleRS) had 917 amino acids with a molecular mass of 105399 Da. which was consistent with the observed sire of 105 kDa in Escheri chia coli maxicells. The ileS gene was mapped onto the physical map of the C. jejuni genome. Alignment of the C. jejuni IleRS sequence with six other bacterial IleRS sequences and two lower eukaryotic IleRS seq uences identified seven conserved motifs, including the two signature sequences, HIGH and KMSKS, of class I aminoacyl-tRNA synthetases.