Phylogenetic tree of the C10 proteases available on the GenBank and NCBI databases. Cluster analysis was based upon the neighbour-joining method. Numbers at branch-points are percentages of 1000 bootstrap re-samplings that support the topology of the tree. The tree was rooted using C47 family cysteine protease sequences (Staphopains). The locus tag identifiers and the organism name are given. SpeB and the Btp proteases are indicated by a red diamond.