3nsb

Structure of bacteriorhodopsin ground state before and after X-ray modification

spinqualitylabelsall models 3nsb, resolution 1.78Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3nsb is a 1 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 1.78Å Ligands: LI1, RET Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function BACR_HALSA Light-driven proton pump. Publication Abstract from PubMed Bacteriorhodopsin (bR) provides light-driven vectorial proton transport across a cell membrane. Creation of electrochemical potential at the membrane is a universal step in energy transformation in a cell. Published atomic crystallographic models of early intermediate states of bR show a significant difference between them, and conclusions about pumping mechanisms have been contradictory. Here, we present a quantitative high-resolution crystallographic study of conformational changes in bR induced by X-ray absorption. It is shown that X-ray doses that are usually accumulated during data collection for intermediate-state studies are sufficient to significantly alter the structure of the protein. X-ray-induced changes occur primarily in the active site of bR. Structural modeling showed that X-ray absorption triggers retinal isomerization accompanied by the disappearance of electron densities corresponding to the water molecule W402 bound to the Schiff base. It is demonstrated that these and other X-ray-induced changes may mimic functional conformational changes of bR leading to misinterpretation of the earlier obtained X-ray crystallographic structures of photointermediates. X-ray-Radiation-Induced Changes in Bacteriorhodopsin Structure.,Borshchevskiy VI, Round ES, Popov AN, Buldt G, Gordeliy VI J Mol Biol. 2011 Apr 21. PMID:21530535 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Bacteriorhodopsin 3D structures

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