Crystal Structure of a ligand-bound LacY-Nanobody Complex.

ABSTRACT: The lactose permease of Escherichia coli (LacY), a dynamic polytopic membrane transport protein, catalyzes galactoside/H⁺ symport and operates by an alternating access mechanism that exhibits multiple conformations, the distribution of which is altered by sugar-binding. Camelid nanobodies were made against a double-mutant Gly46 → Trp/Gly262 → Trp (LacY_WW) that produces an outward-open conformation, as opposed to the cytoplasmic open-state crystal structure of WT LacY. Nanobody 9047 (Nb9047) stabilizes WT LacY in a periplasmic-open conformation. Here, we describe the X-ray crystal structure of a complex between LacY_WW, the high-affinity substrate analog 4-nitrophenyl-α-d-galactoside (NPG), and Nb9047 at 3-Å resolution. The present crystal structure de

SUBMITTER: Kumar H 

PROVIDER: S-EPMC6126719 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature