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Isopenicillin N synthase d-(L-a-aminoadipoyl)-(3R)-methyl-L-cysteine D-a-hydroxyisovaleryl ester complex (Oxygen exposed 5 minutes 20 bar)Isopenicillin N synthase d-(L-a-aminoadipoyl)-(3R)-methyl-L-cysteine D-a-hydroxyisovaleryl ester complex (Oxygen exposed 5 minutes 20 bar)
Structural highlights
Function[IPNS_EMENI] Removes, in the presence of oxygen, 4 hydrogen atoms from delta-L-(alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) to form the azetidinone and thiazolidine rings of isopenicillin. 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 PubMedIsopenicillin N synthase (IPNS) is a non-heme iron(ii)-dependent oxidase that is central to penicillin biosynthesis. Herein, we report mechanistic studies of the IPNS reaction in the crystalline state, using the substrate analogue delta-(L-alpha-aminoadipoyl)-(3R)-methyl-L-cysteine D-alpha-hydroxyisovaleryl ester (AmCOV) to probe the early stages of the catalytic cycle. The X-ray crystal structure of the anaerobic IPNS:Fe(II):AmCOV complex was solved to 1.40 A resolution, and it reveals several subtle differences in the active site relative to the complex of the enzyme with its natural substrate. The crystalline IPNS:Fe(II):AmCOV complex was then exposed to oxygen gas at high pressure; this brought about reaction to give what appears to be a hydroxymethyl/ene-thiol product. A mechanism for this reaction is proposed. These results offer further insight into the delicate interplay of steric and electronic effects in the IPNS active site and the mechanistic intricacies of this remarkable enzyme. Unexpected oxidation of a depsipeptide substrate analogue in crystalline isopenicillin N synthase.,Daruzzaman A, Clifton IJ, Adlington RM, Baldwin JE, Rutledge PJ Chembiochem. 2006 Feb;7(2):351-8. PMID:16444759[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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