FIGURE 2.

Blocking of Pfpro‐PMX active site by the twisted loop of the prosegment and inhibitory arginine (R244). (a) The prosegment is shown as an electrostatic surface (blue: positive, red: negative and white: neutral) and the mature part of the enzyme in green and flap is in orange cartoon representation. The inset shows the zoomed in‐view of the twisted loop blocking the active site. (b) The twisted loop region blocks the active site residues (D266 and D457, blue ball and stick). The β3 and following twisted loop region are held by multiple interactions. (c) The structure of Pfpro‐PMX highlighting blockage of the catalytic aspartates (D266 and D457) by R244 mediated through salt bridge interactions. Inset shows 2F _o –F _c electron density map contoured at 1σ level around R244, D266, and D457. The other neighboring residues of catalytic aspartates are also shown. (d) Conservation of the residues of the twisted loop, inhibitory R244, and the catalytic motifs in PMX zymogens from other human malaria‐causing Plasmodium species [P. falciparum (Pf), P. vivax (Pv), P. knowlesi (Pk), P. ovalae (Po)]