View source for 1ptm


==Crystal structure of E.coli PdxA==
<StructureSection load='1ptm' size='340' side='right'caption='[[1ptm]], [[Resolution|resolution]] 1.96&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ptm]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PTM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PTM 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]] 1.96&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=1ptm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ptm OCA], [https://pdbe.org/1ptm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ptm RCSB], [https://www.ebi.ac.uk/pdbsum/1ptm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ptm ProSAT], [https://www.topsan.org/Proteins/BSGI/1ptm TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PDXA_ECOLI PDXA_ECOLI] Catalyzes the NAD(P)-dependent oxidation of 4-(phosphohydroxy)-L-threonine (HTP) into 2-amino-3-oxo-4-(phosphohydroxy)butyric acid which spontaneously decarboxylates to form 3-amino-2-oxopropyl phosphate (AHAP).[REFERENCE:5]<ref>PMID:15026039</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/pt/1ptm_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1ptm ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Pyridoxal 5'-phosphate is an essential cofactor for many enzymes responsible for the metabolic conversions of amino acids. Two pathways for its de novo synthesis are known. The pathway utilized by Escherichia coli consists of six enzymatic steps catalyzed by six different enzymes. The fourth step is catalyzed by 4-hydroxythreonine-4-phosphate dehydrogenase (PdxA, E.C. 1.1.1.262), which converts 4-hydroxy-l-threonine phosphate (HTP) to 3-amino-2-oxopropyl phosphate. This divalent metal ion-dependent enzyme has a strict requirement for the phosphate ester form of the substrate HTP, but can utilize either NADP+ or NAD+ as redox cofactor. We report the crystal structure of E. coli PdxA and its complex with HTP and Zn2+. The protein forms tightly bound dimers. Each monomer has an alpha/beta/alpha-fold and can be divided into two subdomains. The active site is located at the dimer interface, within a cleft between the two subdomains and involves residues from both monomers. A Zn2+ ion is bound within each active site, coordinated by three conserved histidine residues from both monomers. In addition two conserved amino acids, Asp247 and Asp267, play a role in maintaining integrity of the active site. The substrate is anchored to the enzyme by the interactions of its phospho group and by coordination of the amino and hydroxyl groups by the Zn2+ ion. PdxA is structurally similar to, but limited in sequence similarity with isocitrate dehydrogenase and isopropylmalate dehydrogenase. These structural similarities and the comparison with a NADP-bound isocitrate dehydrogenase suggest that the cofactor binding mode of PdxA is very similar to that of the other two enzymes and that PdxA catalyzes a stepwise oxidative decarboxylation of the substrate HTP.

Crystal structure of Escherichia coli PdxA, an enzyme involved in the pyridoxal phosphate biosynthesis pathway.,Sivaraman J, Li Y, Banks J, Cane DE, Matte A, Cygler M J Biol Chem. 2003 Oct 31;278(44):43682-90. Epub 2003 Aug 1. PMID:12896974<ref>PMID:12896974</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1ptm" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Banks J]]
[[Category: Cane DE]]
[[Category: Cygler M]]
[[Category: Li Y]]
[[Category: Matte A]]
[[Category: Sivaraman J]]