Schematic diagrams of the domain structures of myroicolsin precursor (A) and structural comparison of myroicolsin and other characterized collagenolytic proteases of the S8 family (B). Myroicolsin, the protease studied here (AEC33275). The possible catalytic triad, Asp34, His79, and Ser283, is indicated by arrows in A. MO-1, the protease secreted by G. collagenovorans MO-1 (AB260948); MCP-01, the protease from Pseudoalteromonas sp. SM9913 (ABD14413); AcpII, the protease from A. collagenimarina AC40 (AB505451).