2cfp
SUGAR FREE LACTOSE PERMEASE AT ACIDIC PH
OverviewOverview
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.
About this StructureAbout this Structure
2CFP is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
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 Page seeded by OCA on Sat May 3 22:01:44 2008