1bk0: Difference between revisions

Revision as of 11:37, 2 May 2008

ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ACV-FE COMPLEX)

OverviewOverview

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 StructureAbout this Structure

1BK0 is a Single protein structure of sequence from Emericella nidulans. Full crystallographic information is available from OCA.

ReferenceReference

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 Page seeded by OCA on Fri May 2 11:37:00 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1bk0.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1bk0 |SIZE=350|CAPTION= <scene name='initialview01'>1bk0</scene>, resolution 1.3&Aring;
+The line below this paragraph, containing "STRUCTURE_1bk0", creates the "Structure Box" on the page.
-|SITE= <scene name='pdbsite=SA:Active+Site+(Fe+Binding)'>SA</scene>
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=ACV:L-D-(A-AMINOADIPOYL)-L-CYSTEINYL-D-VALINE'>ACV</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY=
+or leave the SCENE parameter empty for the default display.
-|GENE= PCB C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=162425 Emericella nidulans])
+-->
-|DOMAIN=
+{{STRUCTURE_1bk0|  PDB=1bk0  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1bk0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bk0 OCA], [http://www.ebi.ac.uk/pdbsum/1bk0 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1bk0 RCSB]</span>
-}}
 '''ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ACV-FE COMPLEX)'''
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 [[Category: Schofield, C J.]]
 [[Category: Shibata, N.]]
-[[Category: b-lactam antibiotic]]
+[[Category: B-lactam antibiotic]]
-[[Category: oxygenase]]
+[[Category: Oxygenase]]
-[[Category: penicillin biosynthesis]]
+[[Category: Penicillin biosynthesis]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 11:37:00 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:02:40 2008''