Fig. 7: Glc displacement routes in WT, and the W434H, and W434A mutants of HvExoI with Glc and laminaripentaose, calculated through cMD and GPathFinder.
From: The evolutionary advantage of an aromatic clamp in plant family 3 glycoside exo-hydrolases
a WT; b W434H; c W434A – Four steps along Glc displacement routes based on converged structures in complex with Glc (−1 subsite; carbons in cpk yellow lines, and spheres) and laminaripentaose (+1 and +2 subsites and bulk solvent; carbons: magenta sticks) obtained by docking. Selected residues (carbons: atomic sticks), and positions of Glc, and laminaripentaose are indicated. Glc in the −1 subsite is separated from the lateral cavity that is evolving during Glc egress by the participation of the Arg158-Asp285-Glu491 toll-like barrier (triangles in dashed lines; distances indicated in Å). Surface morphologies of structures are coloured by electrostatic potentials: white, neutral; blue, +5 kT·e−1; red, −5 kT·e−1. Separations in Å between the positions of C1 carbons of Glc molecules, as they move from the −1 subsites in initial and final structures are indicated. The lateral cavity (a, b; indicated in black dotted ellipsoids) forms transiently, is partly exposed to bulk solvent, and facilitates Glc displacement. In panel c, Glc is displaced to bulk solvent through the opening formed by the W434A mutation.
