3zk7

CRYSTAL STRUCTURE OF PNEUMOCOCCAL SURFACE ANTIGEN PSAA IN THE METAL-FREE, OPEN STATE

spinqualitylabelsall models 3zk7, resolution 1.69Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3zk7 is a 2 chain structure with sequence from Streptococcus pneumoniae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.69Å Ligands: TRS Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MTSA_STRPN Part of an ATP-driven transport system for manganese. Also act as an adhesin which is involved on adherence to extracellular matrix. It is an important factor in pathogenesis and infection. Publication Abstract from PubMed The relative stability of divalent first-row transition metal ion complexes, as defined by the Irving-Williams series, poses a fundamental chemical challenge for selectivity in bacterial metal ion acquisition. Here we show that although the substrate-binding protein of Streptococcus pneumoniae, PsaA, is finely attuned to bind its physiological substrate manganese, it can also bind a broad range of other divalent transition metal cations. By combining high-resolution structural data, metal-binding assays and mutational analyses, we show that the inability of open-state PsaA to satisfy the preferred coordination chemistry of manganese enables the protein to undergo the conformational changes required for cargo release to the Psa permease. This is specific for manganese ions, whereas zinc ions remain bound to PsaA. Collectively, these findings suggest a new ligand binding and release mechanism for PsaA and related substrate-binding proteins that facilitate specificity for divalent cations during competition from zinc ions, which are more abundant in biological systems. Imperfect coordination chemistry facilitates metal ion release in the Psa permease.,Counago RM, Ween MP, Begg SL, Bajaj M, Zuegg J, O'Mara ML, Cooper MA, McEwan AG, Paton JC, Kobe B, McDevitt CA Nat Chem Biol. 2013 Nov 10. doi: 10.1038/nchembio.1382. PMID:24212134 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Adhesin 3D structures

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