Figure 3

Phylogenetic tree of enzymes in the subtilase superfamily based on amino acid sequence similarity in catalytic domains. The bootstrap consensus tree inferred from 1000 replicates was taken to represent the evolutionary history of the sequence analyzed. Branches corresponding to partitions reproduced in less than 50% bootstrap replicates are collapsed. The percentage of replicate trees in which the associated sequence clustered together in the bootstrap test (1000 replicates) is shown next to the branches. All positions containing gaps and missing data were eliminated from the dataset (Complete deletion option). There were a total of 66 positions in the final dataset. The subtilase superfamily is classified as recommended by Siezen et al [4] (square brackets). The subtilisin family is subdivided into true subtilisins, phylogenetically intermediate subtilisins between true subtilisins and high-alkaline protease (PIS), high-alkaline proteases, high-molecular-mass subtilisins (HMS), and intracellular subtilisins [17] (dotted square brackets). AprX-SK37 from Virgibacillus sp. SK37 in this study (underlined) is a member of the novel AprX family. Black dots indicate oxidant stable proteases (OSPs). The newly classified alkaline serine protease X (AprX) family (dashed square bracket), proposed in this study is marked with a star.