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Figure 3
Metallopeptidase zymogens with short PSs. (a) A ribbon-type plot of T. forsythia promirolysin (PDB entry 6r7v; this work) with the PS in salmon and the CD in pale blue. The catalytic zinc and the structural calcium cations are shown as magenta and blue spheres, respectively. The side chains of the three histidine zinc ligands are shown as yellow sticks, the PS residue blocking the zinc is in green. (b) Same as (a) depicting human promeprin β (PDB entry 4gwm; Arolas et al., 2012BB5). The C-terminal TRAF domain, along which the N-terminal segment of the PS runs, is shown in white for reference. (c) A. astacus proastacin (PDB entry 3lq0; Guevara et al., 2010BB38). (d) T. forsythia prokarilysin (PDB entry 4r3v; López-Pelegrín et al., 2015BB67). (e) Promyroilysin from Myroides sp. CSLB8 (PDB entry 5gwd; Xu et al., 2017BB102). Uniquely among these MP zymogens, the PS is covered here by a flap (Thr160–Asp193, in blue), which is folded outward upon activation to liberate the cleft.

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ISSN: 2052-2525