6m5q

A class C beta-lactamase mutant - Y150F

spinqualitylabelsall models 6m5q, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.3Å Ligands: IM2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The hydrolysis of beta-lactam antibiotics by class C beta-lactamases proceeds through the acylation and the rate-determining deacylation steps mediated by the nucleophilic serine and the deacylation water, respectively. The pose of poor substrates such as carbapenems in the acylated enzyme is responsible for the low efficient deacylation reaction. Here we present the crystal structures of the Y150F variant of the ACC-1 class C beta-lactamase in the apo and acylated states. In the acylated enzyme complexed with two carbapenems, imipenem and meropenem, the lactam carbonyl oxygen is located in the oxyanion hole. However, the five-membered pyrroline ring displays a novel orientation that has not been reported so far. The ring is rotated such that its C3 carboxylate makes salt bridges with Lys67 and Ly315, which is accompanied by the side-chain rotamer change of Phe150. The C3 carboxylate is placed where the deacylation water occupies in the apo-enzyme, which, together with the displacement of the catalytic base residue at position 150, explains why carbapenems are poor substrates of ACC-1. Novel inhibition mechanism of carbapenems on the ACC-1 class C beta-lactamase.,Bae DW, Jung YE, Jeong BG, Cha SS Arch Biochem Biophys. 2020 Oct 30;693:108570. doi: 10.1016/j.abb.2020.108570., Epub 2020 Sep 1. PMID:32888908 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Beta-lactamase 3D structures

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