4q8i

Crystal Structure of beta-lactamase from M.tuberculosis covalently complexed with Tebipenem

spinqualitylabelsall models 4q8i, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4q8i is a 1 chain structure with sequence from Mycobacterium tuberculosis H37Rv. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.901Å Ligands: PO4, TEB Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function BLAC_MYCTU Publication Abstract from PubMed The genome of Mycobacterium tuberculosis contains a gene, blaC, which encodes a highly active beta-lactamase (BlaC). We have previously shown that BlaC has an extremely broad spectrum of activity against penicillins and cephalosporins but weak activity against newer carbapenems. We have shown that carbapenems such as meropenem, doripenem, and ertapenem react with the enzyme to form enzyme-drug covalent complexes that are hydrolyzed extremely slowly. In the current study, we have determined apparent Km and kcat values of 0.8 muM and 0.03 min(-1), respectively, for tebipenem, a novel carbapenem whose prodrug form, the pivalyl ester, is orally available. Tebipenem exhibits slow tight-binding inhibition at low micromolar concentrations versus the chromogenic substrate nitrocefin. FT-ICR mass spectrometry demonstrated that the tebipenem acyl-enzyme complex remains stable for greater than 90 min and exists as mixture of the covalently bound drug and the bound retro-aldol cleavage product. We have also determined the high-resolution crystal structures of the BlaC-tebipenem covalent acylated adduct (1.9 A) with wild-type BlaC and the BlaC-tebipenem Michaelis-Menten complex (1.75 A) with the K73A BlaC variant. These structures are compared to each other and to other carbapenem-BlaC structures. Tebipenem, a new carbapenem antibiotic, is a slow substrate that inhibits the beta-lactamase from Mycobacterium tuberculosis.,Hazra S, Xu H, Blanchard JS Biochemistry. 2014 Jun 10;53(22):3671-8. doi: 10.1021/bi500339j. Epub 2014 May, 29. PMID:24846409 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Beta-lactamase 3D structures

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