2jvg | pdb_00002jvg

Structure of C3-binding domain 4 of Staphylococcus aureus protein Sbi

spinqualitylabelsall models 2jvg, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2jvg is a 1 chain structure with sequence from "micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 2gom, 2noj, 2qff, 2jvh Gene: sbi ("Micrococcus aureus" (Rosenbach 1884) Zopf 1885) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [SBI_STAAN] Interacts with components of both the adaptive and innate host immune system, thereby protecting the cell against the host immune response. Publication Abstract from PubMed Among the recently discovered Staphylococcus aureus immune evasion proteins, Sbi is unique in its ability to interact with components of both the adaptive and innate immune systems of the host. Sbi domains I and II (Sbi-I and Sbi-II) bind IgG. Sbi domain IV (residues 198-266) binds the central complement protein C3. When linked to Sbi-III, Sbi-IV induces a futile consumption of complement via alternative pathway activation, whereas isolated Sbi-IV specifically inhibits the alternative pathway without complement consumption. Here we have determined the three-dimensional structure of Sbi-IV by NMR spectroscopy, showing that Sbi-IV adopts a three-helix bundle fold similar to those of the S. aureus complement inhibitors Efb-C, Ehp, and SCIN. The (1)H-(15)N HSQC spectrum of Sbi-III indicates that this domain, essential for futile complement consumption, is natively unfolded, at least when isolated from the rest of Sbi. Sbi-IV and Sbi-III-IV both bind C3dg with 1:1 stoichiometry and submicromolar affinity. Despite low overall sequence identity, Sbi possesses the same residues as Efb at two positions essential for Efb-C binding to C3d. Mutation to alanine of either of these residues, Arg-231 and Asn-238, abolishes both Sbi-IV binding to C3dg and Sbi-IV alternative pathway inhibition. The almost complete conservation of Sbi-III and Sbi-IV amino acid sequences across more than 30 strains isolated from human and animal hosts indicates that the unique mechanism of Sbi in complement system subversion is a feature of infections of both humans and economically important animals. Structure-function analysis of the C3 binding region of Staphylococcus aureus immune subversion protein Sbi.,Upadhyay A, Burman JD, Clark EA, Leung E, Isenman DE, van den Elsen JM, Bagby S J Biol Chem. 2008 Aug 8;283(32):22113-20. Epub 2008 Jun 11. PMID:18550524 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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