3n8d

Crystal structure of Staphylococcus aureus VRSA-9 D-Ala:D-Ala ligase

spinqualitylabelsall models 3n8d, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3n8d is a 2 chain structure with sequence from Staphylococcus aureus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.3Å Ligands: ANP, CL, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DDL_STAAC Cell wall formation (By similarity). Publication Abstract from PubMed The vancomycin-resistant Staphylococcus aureus VRSA-9 clinical isolate was partially dependent on glycopeptide for growth. The responsible vanA operon had the same organization as that of Tn1546 and was located on a plasmid. The chromosomal D-Ala:D-Ala ligase (ddl) gene had two point mutations that led to Q260K and A283E substitutions, resulting in a 200-fold decrease in enzymatic activity compared to that of the wild-type strain VRSA-6. To gain insight into the mechanism of enzyme impairment, we determined the crystal structure of VRSA-9 Ddl and showed that the A283E mutation induces new ion pair/hydrogen bond interactions, leading to an asymmetric rearrangement of side chains in the dimer interface. The Q260K substitution is located in an exposed external loop and did not induce any significant conformational change. The VRSA-9 strain was susceptible to oxacillin due to synthesis of pentadepsipeptide precursors ending in D-alanyl-D-lactate which are not substrates for the beta-lactam-resistant penicillin binding protein PBP2'. Comparison with the partially vancomycin-dependent VRSA-7, whose Ddl is 5-fold less efficient than that of VRSA-9, indicated that the levels of vancomycin dependence and susceptibility to beta-lactams correlate with the degree of Ddl impairment. Ddl drug targeting could therefore be an effective strategy against vancomycin-resistant S. aureus. Molecular basis of vancomycin dependence in VanA-type Staphylococcus aureus VRSA-9.,Meziane-Cherif D, Saul FA, Moubareck C, Weber P, Haouz A, Courvalin P, Perichon B J Bacteriol. 2010 Oct;192(20):5465-71. Epub 2010 Aug 20. PMID:20729361 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also D-alanine-D-alanine ligase 3D structures

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