2ov1

Crystal structure of apo form of ZnuA with flexible loop deletion

spinqualitylabelsall models 2ov1, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ov1 is a 1 chain structure with sequence from Synechocystis sp. PCC 6803 substr. Kazusa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function P73085_SYNY3 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 A number of bacterial metal transporters belong to the ABC transporter family. To better understand the structural determinants of metal selectivity of one such transporter, we previously determined the structure of the periplasmic domain of a zinc transporter, ZnuA, from Synechocystis 6803 and found that ZnuA binds zinc via three histidines. Unique to these ABC zinc transporters, ZnuA has a highly charged and mobile loop that protrudes from the protein in the vicinity of the metal binding site that we had suggested might facilitate zinc acquisition. To further examine the function of this loop, the structure and zinc binding properties of two ZnuA variants were determined. When the loop is entirely deleted, zinc still binds to the three histidines. However, unlike what was suggested from the structure of a similar solute binding protein, TroA, release of zinc occurs concomitantly with large conformational changes in two of the three chelating histidines. These structural results combined with isothermal titration calorimetry data demonstrate that there are at least two classes of zinc binding sites: the high-affinity site in the cleft between the two domains and at least one additional site on the flexible loop. This loop has approximately 100-fold weaker affinity for zinc than the high-affinity zinc binding site, and its deletion does not affect the high-affinity site. From these results, we suggest that this region might be a sensor for high periplasmic levels of zinc. Possible regulatory role for the histidine-rich loop in the zinc transport protein, ZnuA.,Wei B, Randich AM, Bhattacharyya-Pakrasi M, Pakrasi HB, Smith TJ Biochemistry. 2007 Jul 31;46(30):8734-43. Epub 2007 Jul 6. PMID:17616151 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ABC transporter 3D structures

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