1w04: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1w04.gif|left|200px]]<br /><applet load="1w04" size=" | [[Image:1w04.gif|left|200px]]<br /><applet load="1w04" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1w04, resolution 1.28Å" /> | caption="1w04, resolution 1.28Å" /> | ||
'''ISOPENICILLIN N SYNTHASE AMINOADIPOYL-CYSTEINYL-GLYCINE-FE-NO COMPLEX'''<br /> | '''ISOPENICILLIN N SYNTHASE AMINOADIPOYL-CYSTEINYL-GLYCINE-FE-NO COMPLEX'''<br /> | ||
| Line 7: | Line 7: | ||
==About this Structure== | ==About this Structure== | ||
1W04 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, SO4, HCG and NO 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] Known structural/functional Site: <scene name='pdbsite=AC1:So4 Binding Site For Chain A'>AC1</scene>. Full crystallographic information is available from [http:// | 1W04 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 <scene name='pdbligand=FE2:'>FE2</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=HCG:'>HCG</scene> and <scene name='pdbligand=NO:'>NO</scene> 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] Known structural/functional Site: <scene name='pdbsite=AC1:So4+Binding+Site+For+Chain+A'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1W04 OCA]. | ||
==Reference== | ==Reference== | ||
| Line 26: | Line 26: | ||
[[Category: penicillin biosynthesis]] | [[Category: penicillin biosynthesis]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 10:17:41 2008'' | ||
Revision as of 11:17, 3 February 2008
|
ISOPENICILLIN N SYNTHASE AMINOADIPOYL-CYSTEINYL-GLYCINE-FE-NO COMPLEX
OverviewOverview
Isopenicillin N synthase (IPNS), a non-heme iron(II)-dependent oxidase, catalyzes conversion of the tripeptide, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (ACV) to bicyclic, isopenicillin N (IPN), concomitant with the reduction of dioxygen to two, molecules of water. Incubation of the "truncated"substrate analogues, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-glycine (ACG) and, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-alanine (ACA) with IPNS has, previously been shown to afford acyclic products, in which the substrate, cysteinyl residue has undergone a two-electron oxidation. We report X-ray, crystal structures for the anaerobic IPNS/Fe(II)/ACG and IPNS/Fe(II)/ACA, complexes, both in the absence and presence of the dioxygen analogue, nitric oxide. The overall protein structures are very similar to those of, the corresponding IPNS/Fe(II)/ACV complexes; however, significant, differences are apparent in the vicinity of the active site iron. The, structure of the IPNS/Fe(II)/ACG complex reveals that the C-terminal, carboxylate of this substrate is oriented toward the active site iron, atom, apparently hydrogen-bonded to an additional water ligand at the, metal; this is a different binding mode to that observed in the, IPNS/Fe(II)/ACV complex. ACA binds to the metal in a manner that is, intermediate between those observed for ACV and ACG. The addition of NO to, these complexes initiates conformational changes such that both the, IPNS/Fe(II)/ACG/NO and IPNS/Fe(II)/ACA/NO structures closely resemble the, IPNS/Fe(II)/ACV/NO complex. These results further demonstrate the, feasibility of metal-centered rearrangements in catalysis by non-heme iron, enzymes and provide insight into the delicate balance between, hydrophilic-hydrophobic interactions and steric effects in the IPNS active, site.
About this StructureAbout this Structure
1W04 is a Single protein structure of sequence from Emericella nidulans with , , and as ligands. Active as Isopenicillin-N synthase, with EC number 1.21.3.1 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Structural studies on the reaction of isopenicillin N synthase with the truncated substrate analogues delta-(L-alpha-aminoadipoyl)-L-cysteinyl-glycine and delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-alanine., Long AJ, Clifton IJ, Roach PL, Baldwin JE, Rutledge PJ, Schofield CJ, Biochemistry. 2005 May 3;44(17):6619-28. PMID:15850395
Page seeded by OCA on Sun Feb 3 10:17:41 2008