1bk0
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The biosynthesis of penicillin and cephalosporin antibiotics in | + | The biosynthesis of penicillin and cephalosporin antibiotics in microorganisms requires the formation of the bicyclic nucleus of penicillin. Isopenicillin N synthase (IPNS), a non-haem iron-dependent oxidase, catalyses the reaction of a tripeptide, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV), and dioxygen to form isopenicillin N and two water molecules. Mechanistic studies suggest the reaction is initiated by ligation of the substrate thiolate to the iron centre, and proceeds through an enzyme-bound monocyclic intermediate. Here we report the crystal structure of IPNS complexed to ferrous iron and ACV, determined to 1.3 A resolution. Based on the structure, we propose a mechanism for penicillin formation that involves ligation of ACV to the iron centre, creating a vacant iron coordination site into which dioxygen can bind. Subsequently, iron-dioxygen and iron-oxo species remove the requisite hydrogens from ACV without the direct assistance of protein residues. The crystal structure of the complex with the dioxygen analogue, NO and ACV bound to the active-site iron supports this hypothesis. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Emericella nidulans]] | [[Category: Emericella nidulans]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Baldwin, J | + | [[Category: Baldwin, J E.]] |
| - | [[Category: Clifton, I | + | [[Category: Clifton, I J.]] |
[[Category: Hajdu, J.]] | [[Category: Hajdu, J.]] | ||
| - | [[Category: Hensgens, C | + | [[Category: Hensgens, C M.H.]] |
| - | [[Category: Roach, P | + | [[Category: Roach, P L.]] |
| - | [[Category: Schofield, C | + | [[Category: Schofield, C J.]] |
[[Category: Shibata, N.]] | [[Category: Shibata, N.]] | ||
[[Category: ACV]] | [[Category: ACV]] | ||
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[[Category: penicillin biosynthesis]] | [[Category: penicillin biosynthesis]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:56:10 2008'' |
Revision as of 09:56, 21 February 2008
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ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ACV-FE COMPLEX)
Overview
The biosynthesis of penicillin and cephalosporin antibiotics in microorganisms requires the formation of the bicyclic nucleus of penicillin. Isopenicillin N synthase (IPNS), a non-haem iron-dependent oxidase, catalyses the reaction of a tripeptide, delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine (ACV), and dioxygen to form isopenicillin N and two water molecules. Mechanistic studies suggest the reaction is initiated by ligation of the substrate thiolate to the iron centre, and proceeds through an enzyme-bound monocyclic intermediate. Here we report the crystal structure of IPNS complexed to ferrous iron and ACV, determined to 1.3 A resolution. Based on the structure, we propose a mechanism for penicillin formation that involves ligation of ACV to the iron centre, creating a vacant iron coordination site into which dioxygen can bind. Subsequently, iron-dioxygen and iron-oxo species remove the requisite hydrogens from ACV without the direct assistance of protein residues. The crystal structure of the complex with the dioxygen analogue, NO and ACV bound to the active-site iron supports this hypothesis.
About this Structure
1BK0 is a Single protein structure of sequence from Emericella nidulans with , and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure of isopenicillin N synthase complexed with substrate and the mechanism of penicillin formation., Roach PL, Clifton IJ, Hensgens CM, Shibata N, Schofield CJ, Hajdu J, Baldwin JE, Nature. 1997 Jun 19;387(6635):827-30. PMID:9194566
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