3fh6
Crystal structure of the resting state maltose transporter from E. coliCrystal structure of the resting state maltose transporter from E. coli
Structural highlights
FunctionMALF_ECOLI Part of the binding-protein-dependent transport system for maltose; probably responsible for the translocation of the substrate across the membrane. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedATP-binding cassette transporters couple ATP hydrolysis to substrate translocation through an alternating access mechanism, but the nature of the conformational changes in a transport cycle remains elusive. Previously we reported the structure of the maltose transporter MalFGK(2) in an outward-facing conformation in which the transmembrane (TM) helices outline a substrate-binding pocket open toward the periplasmic surface and ATP is poised for hydrolysis along the closed nucleotide-binding dimer interface. Here we report the structure of the nucleotide-free maltose transporter in which the substrate binding pocket is only accessible from the cytoplasm and the nucleotide-binding interface is open. Comparison of the same transporter crystallized in two different conformations reveals that alternating access involves rigid-body rotations of the TM subdomains that are coupled to the closure and opening of the nucleotide-binding domain interface. The comparison also reveals that point mutations enabling binding protein-independent transport line dynamic interfaces in the TM region. Alternating access in maltose transporter mediated by rigid-body rotations.,Khare D, Oldham ML, Orelle C, Davidson AL, Chen J Mol Cell. 2009 Feb 27;33(4):528-36. PMID:19250913[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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