Fig. 5: Regioselectivity in the GH3 family is associated with the product release area.
a Surface representation of CapGH3a highlighting the productive binding of gentiobiose, stabilized by interactions of the +1 glucoside with the aromatic residue Trp88 (Supplementary Fig. 27). The depicted structure is a representative frame of the molecular dynamics simulation. b–d Substrate saturation curves of CapGH3a WT and mutant W88A with gentiobiose, laminaribiose, and cellobiose, respectively, including the kcat values for each substrate. Results are expressed as mean ± s.d. from three independent experiments (n = 3). Kinetics parameters are shown in Table 3. e Productive binding of laminaribiose into CapGH3b. f Unproductive binding of gentiobiose into CapGH3b. The structures are representative frames of molecular dynamics simulations. The zones shadowed in blue highlight the hydrophobic interactions at the +1 subsite by the two face-to-face tryptophan residues. g Root-mean-square deviations (RMSD) of CapGH3b molecular dynamics (MD) trajectories with gentiobiose and laminaribiose.
