FIG 1.

Primary structure and domain organization of TSS and its homologs. (A) Amino acid sequence alignment of TSS (OBR56241) with KP-43 (AB051423). The regions of the signal peptide, the N-terminal propeptide, the catalytic domain, the β-jelly roll domain, and the PPC domain are indicated. The catalytic residues and the Ca²⁺-binding residues (Ca1, Ca2, Ca3, and Ca4) are marked. (B) Comparison of the domain organization of TSS with those of characterized subtilisin-like collagenolytic proteases, including myroicolsin (AEC33275), MCP-01 (ABD14413), AcpII (AB505451), and MO-1 (AB260948). The regions of the mature enzymes are indicated (between the dashed lines).