Fig. 2.

Comparative analysis of isoleucyl-tRNA synthetase sequences. Multiple-sequence alignment of bacterial isoleucyl-tRNA synthetases displaying various levels of susceptibility to mupirocin (resistant versus susceptible) (a). When there are multiple ileS gene copies in the same organism (e.g., ileS2 of S. aureus and ileS2 of P. fluorescens), both of the protein sequences encoded are displayed. The amino acid residues constituting the RG1 and RG2 regions are highlighted. (b) Comparative schematic representation of the ileS locus of B. bifidum PRL2010 and those of various other bifidobacterial strains. Each arrow indicates an open reading frame, the size of which is proportional to the length of the arrow. The predicted function of the protein is indicated above each arrow.