3n4v | pdb_00003n4v

apo APH(2")-IVa form III

spinqualitylabelsall models 3n4v, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3n4v is a 2 chain structure with sequence from Enterococcus casseliflavus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 3n4t, 3n4u Gene: aph(2)-Id (Enterococcus casseliflavus) Resources: FirstGlance, OCA, RCSB, PDBsum 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 Acquired resistance to aminoglycoside antibiotics primarily results from deactivation by three families of aminoglycoside-modifying enzymes. Here we report the kinetic mechanism and structure of the aminoglycoside phosphotransferase 2"-IVa (APH(2")-IVa), an enzyme responsible for resistance to aminoglycoside antibiotics in clinical enterococcal and staphylococcal isolates. The enzyme operates via a Bi Bi sequential mechanism in which the two substrates (ATP or GTP and an aminoglycoside) bind in a random manner. The APH(2")-IVa enzyme phosphorylates various 4,6-disubstituted aminoglycoside antibiotics with catalytic efficiencies (k(cat)/K(m)) of 1.5 x 10(3) to 1.2 x 10(6) (M(-1) s(-1)). The enzyme uses both ATP and GTP as the phosphate source, an extremely rare occurrence in the phosphotransferase and protein kinase enzymes. Based upon an analysis of the APH(2")-IVa structure, two overlapping binding templates specifically tuned for hydrogen bonding to either ATP or GTP have been identified and described. A detailed understanding of the structure and mechanism of the GTP-utilizing phosphotransferases is crucial for the development of either novel aminoglycosides or, more importantly, GTP-based enzyme inhibitors which would not be expected to interfere with crucial ATP-dependent enzymes. Crystal structure and kinetic mechanism of aminoglycoside phosphotransferase-2-IVa.,Toth M, Frase H, Antunes NT, Smith CA, Vakulenko SB Protein Sci. 2010 Jun 15. PMID:20556826 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phosphotransferase

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