1hb1: Difference between revisions
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[[Image:1hb1.jpg|left|200px]] | [[Image:1hb1.jpg|left|200px]] | ||
'''ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ANAEROBIC ACOV FE COMPLEX)''' | {{Structure | ||
|PDB= 1hb1 |SIZE=350|CAPTION= <scene name='initialview01'>1hb1</scene>, resolution 1.55Å | |||
|SITE= <scene name='pdbsite=OCV:Active+Site+(Fe+Binding)'>OCV</scene> | |||
|LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=FE2:FE+(II)+ION'>FE2</scene> and <scene name='pdbligand=OCV:N6-[(1R)-2-{[(1R)-1-CARBOXY-2-METHYLPROPYL]OXY}-1-(MERCAPTOMETHYL)-2-OXOETHYL]-6-OXO-D-LYSINE'>OCV</scene> | |||
|ACTIVITY= | |||
|GENE= PCB C ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=162425 Emericella nidulans]) | |||
}} | |||
'''ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ANAEROBIC ACOV FE COMPLEX)''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1HB1 is a [ | 1HB1 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Emericella_nidulans Emericella nidulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HB1 OCA]. | ||
==Reference== | ==Reference== | ||
Alternative oxidation by isopenicillin N synthase observed by X-ray diffraction., Ogle JM, Clifton IJ, Rutledge PJ, Elkins JM, Burzlaff NI, Adlington RM, Roach PL, Baldwin JE, Chem Biol. 2001 Dec;8(12):1231-7. PMID:[http:// | Alternative oxidation by isopenicillin N synthase observed by X-ray diffraction., Ogle JM, Clifton IJ, Rutledge PJ, Elkins JM, Burzlaff NI, Adlington RM, Roach PL, Baldwin JE, Chem Biol. 2001 Dec;8(12):1231-7. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11755401 11755401] | ||
[[Category: Emericella nidulans]] | [[Category: Emericella nidulans]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: penicillin biosynthesis]] | [[Category: penicillin biosynthesis]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:34:43 2008'' | ||
Revision as of 12:34, 20 March 2008
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| , resolution 1.55Å | |||||||
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| Sites: | |||||||
| Ligands: | , and | ||||||
| Gene: | PCB C (Emericella nidulans) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (ANAEROBIC ACOV FE COMPLEX)
OverviewOverview
BACKGROUND: Isopenicillin N synthase (IPNS) catalyses formation of bicyclic isopenicillin N, precursor to all penicillin and cephalosporin antibiotics, from the linear tripeptide delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-valine. IPNS is a non-haem iron(II)-dependent enzyme which utilises the full oxidising potential of molecular oxygen in catalysing the bicyclisation reaction. The reaction mechanism is believed to involve initial formation of the beta-lactam ring (via a thioaldehyde intermediate) to give an iron(IV)-oxo species, which then mediates closure of the 5-membered thiazolidine ring. RESULTS: Here we report experiments employing time-resolved crystallography to observe turnover of an isosteric substrate analogue designed to intercept the catalytic pathway at an early stage. Reaction in the crystalline enzyme-substrate complex was initiated by the application of high-pressure oxygen, and subsequent flash freezing allowed an oxygenated product to be trapped, bound at the iron centre. A mechanism for formation of the observed thiocarboxylate product is proposed. CONCLUSIONS: In the absence of its natural reaction partner (the N-H proton of the L-cysteinyl-D-valine amide bond), the proposed hydroperoxide intermediate appears to attack the putative thioaldehyde species directly. These results shed light on the events preceding beta-lactam closure in the IPNS reaction cycle, and enhance our understanding of the mechanism for reaction of the enzyme with its natural substrate.
About this StructureAbout this Structure
1HB1 is a Single protein structure of sequence from Emericella nidulans. Full crystallographic information is available from OCA.
ReferenceReference
Alternative oxidation by isopenicillin N synthase observed by X-ray diffraction., Ogle JM, Clifton IJ, Rutledge PJ, Elkins JM, Burzlaff NI, Adlington RM, Roach PL, Baldwin JE, Chem Biol. 2001 Dec;8(12):1231-7. PMID:11755401
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