Phylogenetic tree based on ArsC proteins. Bootstrap values (expressed as percentages) based on 100 attempts are indicated at the branch points. The accession numbers for the protein sequences are as follows: Y. enterocolitica pYVe227, AAD16858; E. coli R46, AAB09628; A. multivorum pKW301, BAA24824; E. coli chromosome, AAC76528; E. coli R773, AAA21096; S. aureus pI258, AAA25638; Staphylococcus xylosus pSX267, AAA27589; B. subtilis skin element, BAA06970; P. aeruginosa chromosome, AAC69644.