1q5j

Crystal structure of bacteriorhodopsin mutant P91A crystallized from bicelles

spinqualitylabelsall models 1q5j, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1q5j is a 2 chain structure with sequence from Halobacterium salinarum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: RET Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function BACR_HALSA Light-driven proton pump. 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 One of the hallmarks of membrane protein structure is the high frequency of transmembrane helix kinks, which commonly occur at proline residues. Because the proline side chain usually precludes normal helix geometry, it is reasonable to expect that proline residues generate these kinks. We observe, however, that the three prolines in bacteriorhodopsin transmembrane helices can be changed to alanine with little structural consequences. This finding leads to a conundrum: if proline is not required for helix bending, why are prolines commonly present at bends in transmembrane helices? We propose an evolutionary hypothesis in which a mutation to proline initially induces the kink. The resulting packing defects are later repaired by further mutation, thereby locking the kink in the structure. Thus, most prolines in extant proteins can be removed without major structural consequences. We further propose that nonproline kinks are places where vestigial prolines were later removed during evolution. Consistent with this hypothesis, at 14 of 17 nonproline kinks in membrane proteins of known structure, we find prolines in homologous sequences. Our analysis allows us to predict kink positions with >90% reliability. Kink prediction indicates that different G protein-coupled receptor proteins have different kink patterns and therefore different structures. The evolution of transmembrane helix kinks and the structural diversity of G protein-coupled receptors.,Yohannan S, Faham S, Yang D, Whitelegge JP, Bowie JU Proc Natl Acad Sci U S A. 2004 Jan 27;101(4):959-63. Epub 2004 Jan 19. PMID:14732697 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Bacteriorhodopsin 3D structures

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