(
2013-09-27)
Munshi, Parthapratim; Stanley, Christopher B; Ghimire-Rijal, Sudipa; Lu, Xun; Myles, Dean A; Cuneo, Matthew J
Background
Members of the periplasmic binding protein (PBP) superfamily utilize a highly conserved inter-domain ligand binding site that adapts to specifically bind a chemically diverse range of ligands. This paradigm of PBP ligand binding specificity was recently altered when the structure of the Thermotoga maritima cellobiose-binding protein (tmCBP) was solved. The tmCBP binding site is bipartite, comprising a canonical solvent-excluded region (subsite one), adjacent to a solvent-filled cavity (subsite two) where specific and semi-specific ligand recognition occur, respectively.