2cfp
Sugar Free Lactose Permease at acidic pHSugar Free Lactose Permease at acidic pH
Structural highlights
FunctionLACY_ECOLI Responsible for transport of beta-galactosides into the cell, with the concomitant import of a proton (symport system). Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCation-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. See AlsoReferences |
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