1hb2: Difference between revisions
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== | ==ISOPENICILLIN N SYNTHASE FROM ASPERGILLUS NIDULANS (OXYGEN EXPOSED PRODUCT FROM ANAEROBIC ACOV FE COMPLEX)== | ||
BACKGROUND: Isopenicillin N synthase (IPNS) catalyses formation of | <StructureSection load='1hb2' size='340' side='right'caption='[[1hb2]], [[Resolution|resolution]] 1.30Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1hb2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Aspergillus_nidulans Aspergillus nidulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HB2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1HB2 FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.3Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FE2:FE+(II)+ION'>FE2</scene>, <scene name='pdbligand=SCV:N6-[(1S)-2-{[(1R)-1-CARBOXY-2-METHYLPROPYL]OXY}-1-(MERCAPTOCARBONYL)-2-OXOETHYL]-6-OXO-L-LYSINE'>SCV</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1hb2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hb2 OCA], [https://pdbe.org/1hb2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1hb2 RCSB], [https://www.ebi.ac.uk/pdbsum/1hb2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1hb2 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/IPNA_EMENI IPNA_EMENI] Isopenicillin N synthase; part of the gene cluster that mediates the biosynthesis of penicillin, the world's most important antibiotic (PubMed:3319778, PubMed:11755401). IpnA catalyzes the cyclization of the tripeptide N-[(5S)-5-amino-5-carboxypentanoyl]-L-cysteinyl-D-valine (LLD-ACV or ACV) to form isopenicillin N (IPN) that contains the beta-lactam nucleus (PubMed:3319778, PubMed:11755401, PubMed:28703303). The penicillin biosynthesis occurs via 3 enzymatic steps, the first corresponding to the production of the tripeptide N-[(5S)-5-amino-5-carboxypentanoyl]-L-cysteinyl-D-valine (LLD-ACV or ACV) by the NRPS acvA. The tripeptide ACV is then cyclized to isopenicillin N (IPN) by the isopenicillin N synthase ipnA that forms the beta-lactam nucleus. Finally, the alpha-aminoadipyl side chain is exchanged for phenylacetic acid by the isopenicillin N acyltransferase penDE to yield penicillin in the peroxisomal matrix (By similarity).[UniProtKB:P08703]<ref>PMID:11755401</ref> <ref>PMID:28703303</ref> <ref>PMID:3319778</ref> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hb/1hb2_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1hb2 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
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. | |||
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<ref>PMID:11755401</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1hb2" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Isopenicillin N synthase|Isopenicillin N synthase]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Aspergillus nidulans]] | |||
[[Category: Large Structures]] | |||
[[Category: Adlington RM]] | |||
[[Category: Baldwin JE]] | |||
[[Category: Burzlaff NI]] | |||
[[Category: Clifton IJ]] | |||
[[Category: Elkins JM]] | |||
[[Category: Ogle JM]] | |||
[[Category: Roach PL]] | |||
[[Category: Rutledge PJ]] | |||