Fig. 2.

Tertiary and primary structure of hK7. (A) Overall structure of hK7_E monomer with the AAF-CMK inhibitor in a stereo ribbon representation. Side chains of the catalytic triad (His⁵⁷, Asp¹⁰², Ser¹⁹⁵), the specificity-determining Asn¹⁸⁹ in the S1 pocket, the oxyanion hole forming Gly¹⁹³, and the double covalently bound inhibitor are depicted as stick models. Important loops are labeled and highlighted in green. (B) Electrostatic surface representation for hK7_I in a hypothetical complex with the modeled peptide Glu-Ala-Leu-Tyr-Leu-Val, occupying the specificity sites S4 to S2′. (C) Sequence alignment of hK7 with the tissue kallikreins hK6, hK1, hK5, and bovine chymotrypsin as a reference for numbering. Residues involved in metal binding are indicated by magenta background, whereas loops are surrounded by boxes.