View source for 2vlh


==Quinonoid intermediate of Citrobacter freundii tyrosine phenol-lyase formed with methionine==
<StructureSection load='2vlh' size='340' side='right'caption='[[2vlh]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vlh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Citrobacter_freundii Citrobacter freundii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VLH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VLH 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=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=P33:3,6,9,12,15,18-HEXAOXAICOSANE-1,20-DIOL'>P33</scene>, <scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=PM9:(2E)-2-{[(Z)-{3-HYDROXY-2-METHYL-5-[(PHOSPHONOOXY)METHYL]PYRIDIN-4(1H)-YLIDENE}METHYL]IMINO}-4-(METHYLSULFANYL)BUTANOIC+ACID'>PM9</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=2vlh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vlh OCA], [https://pdbe.org/2vlh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vlh RCSB], [https://www.ebi.ac.uk/pdbsum/2vlh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vlh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TPL_CITFR TPL_CITFR] 
== 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/vl/2vlh_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=2vlh ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Amino acid transformations catalyzed by a number of pyridoxal 5'-phosphate (PLP)-dependent enzymes involve abstraction of the Calpha proton from an external aldimine formed between a substrate and the cofactor leading to the formation of a quinonoid intermediate. Despite the key role played by the quinonoid intermediates in the catalysis by PLP-dependent enzymes, limited accurate information is available about their structures. We trapped the quinonoid intermediates of Citrobacter freundii tyrosine phenol-lyase with L-alanine and L-methionine in the crystalline state and determined their structures at 1.9- and 1.95-A resolution, respectively, by cryo-crystallography. The data reveal a network of protein-PLP-substrate interactions that stabilize the planar geometry of the quinonoid intermediate. In both structures the protein subunits are found in two conformations, open and closed, uncovering the mechanism by which binding of the substrate and restructuring of the active site during its closure protect the quinonoid intermediate from the solvent and bring catalytically important residues into positions suitable for the abstraction of phenol during the beta-elimination of L-tyrosine. In addition, the structural data indicate a mechanism for alanine racemization involving two bases, Lys-257 and a water molecule. These two bases are connected by a hydrogen bonding system allowing internal transfer of the Calpha proton.

Insights into the catalytic mechanism of tyrosine phenol-lyase from X-ray structures of quinonoid intermediates.,Milic D, Demidkina TV, Faleev NG, Matkovic-Calogovic D, Antson AA J Biol Chem. 2008 Oct 24;283(43):29206-14. Epub 2008 Aug 20. PMID:18715865<ref>PMID:18715865</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 2vlh" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tyrosinase 3D structures|Tyrosinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Citrobacter freundii]]
[[Category: Large Structures]]
[[Category: Antson AA]]
[[Category: Demidkina TV]]
[[Category: Matkovic-Calogovic D]]
[[Category: Milic D]]