1w3v: Difference between revisions
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==Overview== | ==Overview== | ||
Isopenicillin 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 .. | Isopenicillin 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. | ||
==About this Structure== | ==About this Structure== | ||
1W3V is a | 1W3V is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Emericella_nidulans Emericella nidulans] with FE2 and MDZ as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Isopenicillin-N_synthase Isopenicillin-N synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.21.3.1 1.21.3.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1W3V OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: penicillin biosynthesis]] | [[Category: penicillin biosynthesis]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:25:43 2007'' | ||
