Publication Abstract from PubMed
Cation-coupled active transport is an essential cellular process found ubiquitously in all living organisms. Here, we present two novel ligand-free X-ray structures of the lactose permease (LacY) of Escherichia coli determined at acidic and neutral pH, and propose a model for the mechanism of coupling between lactose and H+ translocation. No sugar-binding site is observed in the absence of ligand, and deprotonation of the key residue Glu269 is associated with ligand binding. Thus, substrate induces formation of the sugar-binding site, as well as the initial step in H+ transduction.
Structural evidence for induced fit and a mechanism for sugar/H+ symport in LacY.,Mirza O, Guan L, Verner G, Iwata S, Kaback HR EMBO J. 2006 Mar 22;25(6):1177-83. Epub 2006 Mar 9. PMID:16525509[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
