3b60

Crystal Structure of MsbA from Salmonella typhimurium with AMPPNP, higher resolution form

spinqualitylabelsall models 3b60, resolution 3.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3b60 is a 4 chain structure with sequence from Salmonella enterica subsp. enterica serovar typhimurium. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ANP Related: 3b5w, 3b5x, 3b5y, 3b5z Gene: msbA (Salmonella enterica subsp. enterica serovar Typhimurium) Resources: FirstGlance, OCA, RCSB, PDBsum Function [MSBA_SALTY] Involved in lipid A export and possibly also in glycerophospholipid export and for biogenesis of the outer membrane. Transmembrane domains (TMD) form a pore in the inner membrane and the ATP-binding domain (NBD) is responsible for energy generation (By similarity). 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 PubMed ATP-binding cassette (ABC) transporters are integral membrane proteins that translocate a wide variety of substrates across cellular membranes and are conserved from bacteria to humans. Here we compare four x-ray structures of the bacterial ABC lipid flippase, MsbA, trapped in different conformations, two nucleotide-bound structures and two in the absence of nucleotide. Comparison of the nucleotide-free conformations of MsbA reveals a flexible hinge formed by extracellular loops 2 and 3. This hinge allows the nucleotide-binding domains to disassociate while the ATP-binding half sites remain facing each other. The binding of the nucleotide causes a packing rearrangement of the transmembrane helices and changes the accessibility of the transporter from cytoplasmic (inward) facing to extracellular (outward) facing. The inward and outward openings are mediated by two different sets of transmembrane helix interactions. Altogether, the conformational changes between these structures suggest that large ranges of motion may be required for substrate transport. Flexibility in the ABC transporter MsbA: Alternating access with a twist.,Ward A, Reyes CL, Yu J, Roth CB, Chang G Proc Natl Acad Sci U S A. 2007 Nov 27;104(48):19005-10. Epub 2007 Nov 16. PMID:18024585 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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