View source for 2oat


==ORNITHINE AMINOTRANSFERASE COMPLEXED WITH 5-FLUOROMETHYLORNITHINE==
<StructureSection load='2oat' size='340' side='right'caption='[[2oat]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2oat]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OAT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2OAT 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PFM:1-AMINO-7-(2-METHYL-3-OXIDO-5-((PHOSPHONOXY)METHYL)-4-PYRIDOXAL-5-OXO-6-HEPTENATE'>PFM</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=2oat FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2oat OCA], [https://pdbe.org/2oat PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2oat RCSB], [https://www.ebi.ac.uk/pdbsum/2oat PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2oat ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/OAT_HUMAN OAT_HUMAN] Defects in OAT are the cause of hyperornithinemia with gyrate atrophy of choroid and retina (HOGA) [MIM:[https://omim.org/entry/258870 258870]. HOGA is a slowly progressive blinding autosomal recessive disorder.<ref>PMID:3375240</ref> <ref>PMID:2793865</ref> <ref>PMID:1612597</ref> <ref>PMID:1737786</ref> <ref>PMID:7887415</ref> <ref>PMID:7668253</ref> 
== Function ==
[https://www.uniprot.org/uniprot/OAT_HUMAN OAT_HUMAN] 
== 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/oa/2oat_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=2oat ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Ornithine aminotransferase (l-ornithine:2-oxoacid delta-aminotransferase; EC 2.6.1.13), a pyridoxal-5'-phosphate-dependent mitochondrial enzyme controls the l-ornithine level in tissues by catalyzing the transfer of the delta-amino group of l-ornithine to 2-oxoglutarate, producing l-glutamate- gamma-semialdehyde and l-glutamate. (2S, 5S)-5-Fluoromethylornithine is the only inhibitor exclusively specific for ornithine aminotransferase known to date. Both in vitro and in vivo, it blocks the enzyme by a suicide reaction leading to a covalent adduct with the cofactor. The crystal structure of the enzyme-inhibitor complex was solved at a resolution of 1.95 A. No significant conformational changes compared with the native enzyme structure were observed. The structure reveals the atomic details of the cofactor-inhibitor adduct and its interactions with the active site of the enzyme. The main residues responsible for specific binding of the inhibitor are Arg180, which forms a strong salt bridge with the alpha-carboxylate and Tyr55, which is involved in a short hydrogen bond with the alpha-amino group. The experimental observation that in the racemic mixture, (2S, 5S)-5-fluoromethylornithine is exclusively responsible for the enzyme inhibition can be explained on the basis of the active site topology. Model building studies strongly suggest that the natural substrate l-ornithine, in its external aldimine adduct with the enzyme, makes use of the same recognition site as the inhibitor. It is proposed that the neutralization of the active site Arg413 by a salt bridge with Glu235 also plays an important role in productive binding of both 5-fluoromethylornithine and l-ornithine. Arg180 and Arg413 are believed to be instrumental in recognition of l-glutamate, by binding its gamma and alpha-carboxylate groups, respectively. This requires a different side-chain conformation of Glu235. Lys292 is the only obvious candidate for catalyzing the rate-limiting proton transfer steps in the transamination reaction.

Crystal structure of human ornithine aminotransferase complexed with the highly specific and potent inhibitor 5-fluoromethylornithine.,Storici P, Capitani G, Muller R, Schirmer T, Jansonius JN J Mol Biol. 1999 Jan 8;285(1):297-309. PMID:9878407<ref>PMID:9878407</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2oat" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aminotransferase 3D structures|Aminotransferase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Schirmer T]]
[[Category: Storici P]]