2vcm | pdb_00002vcm

ISOPENICILLIN N SYNTHASE WITH SUBSTRATE ANALOGUE ASMCOV

spinqualitylabelsall models 2vcm, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vcm is a 1 chain structure with sequence from Emericella nidulans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FE2, M11, SO4 Related: 1hb1, 1ips, 1oc1, 1w04, 1w05, 1w3v, 2bjs, 2jb4, 2vau, 2vbd, 2vbp, 1bk0, 1blz, 1hb2, 1hb3, 1hb4, 1obn, 1odm, 1odn, 1qiq, 1qje, 1qjf, 1uzw, 1w03, 1w06, 1w3x, 2bu9, 2ivi, 2ivj, 2vbb Activity: Isopenicillin-N synthase, with EC number 1.21.3.1 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 Isopenicillin N synthase (IPNS) is a nonheme iron(II)-dependent oxidase that catalyses the central step in penicillin biosynthesis, conversion of the tripeptide delta-L-alpha-aminoadipoyl-L-cysteinyl-D-valine (ACV) to isopenicillin N (IPN). This report describes mechanistic studies using the analogue delta-(L-alpha-aminoadipoyl)-(3S-methyl)-L-cysteine D-alpha-hydroxyisovaleryl ester (A(S)mCOV), designed to intercept the catalytic cycle at an early stage. A(S)mCOV incorporates two modifications from the natural substrate: the second and third residues are joined by an ester, so this analogue lacks the key amide of ACV and cannot form a beta-lactam; and the cysteinyl residue is substituted at its beta-carbon, bearing a (3S)-methyl group. It was anticipated that this methyl group will impinge directly on the site in which the co-substrate dioxygen binds. The novel depsipeptide A(S)mCOV was prepared in 13 steps and crystallised with IPNS anaerobically. The 1.65 A structure of the IPNS-Fe(II)-A(S)mCOV complex reveals that the additional beta-methyl group is not oriented directly into the oxygen binding site, but does increase steric demand in the active site and increases disorder in the position of the isovaleryl side chain. Crystals of IPNS-Fe(II)-A(S)mCOV were incubated with high-pressure oxygen gas, driving substrate turnover to a single product, an ene-thiol/C-hydroxylated depsipeptide. A mechanism is proposed for the reaction of A(S)mCOV with IPNS, linking this result to previous crystallographic studies with related depsipeptides and solution-phase experiments with cysteine-methylated tripeptides. This result demonstrates that a (3S)-methyl group at the substrate cysteinyl beta-carbon is not in itself a block to IPNS activity as previously proposed, and sheds further light on the steric complexities of IPNS catalysis. Structural studies on the reaction of isopenicillin N synthase with a sterically demanding depsipeptide substrate analogue.,Ge W, Clifton IJ, Howard-Jones AR, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ Chembiochem. 2009 Aug 17;10(12):2025-31. PMID:19598184 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Isopenicillin N synthase

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