View source for 2pkr


==Crystal structure of (A+CTE)4 chimeric form of photosyntetic glyceraldehyde-3-phosphate dehydrogenase, complexed with NADP==
<StructureSection load='2pkr' size='340' side='right'caption='[[2pkr]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2pkr]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Spinacia_oleracea Spinacia oleracea]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PKR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PKR 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NDP:NADPH+DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NDP</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=2pkr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pkr OCA], [https://pdbe.org/2pkr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2pkr RCSB], [https://www.ebi.ac.uk/pdbsum/2pkr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2pkr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/G3PA_SPIOL G3PA_SPIOL] 
== 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/pk/2pkr_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=2pkr ConSurf].
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== Publication Abstract from PubMed ==
Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a light-regulated, NAD(P)H-dependent enzyme involved in plant photosynthetic carbon reduction. Unlike lower photosynthetic organisms, which only contain A(4)-GAPDH, the major GAPDH isoform of land plants is made up of A and B subunits, the latter containing a C-terminal extension (CTE) with fundamental regulatory functions. Light-activation of AB-GAPDH depends on the redox state of a pair of cysteines of the CTE, which can form a disulfide bond under control of thioredoxin f, leading to specific inhibition of the NADPH-dependent activity. The tridimensional structure of A(2)B(2)-GAPDH from spinach chloroplasts, crystallized in the oxidized state, shows that each disulfide-containing CTE is docked into a deep cleft between a pair of A and B subunits. The structure of the CTE was derived from crystallographic data and computational modeling and confirmed by site-specific mutagenesis. Structural analysis of oxidized A(2)B(2)-GAPDH and chimeric mutant [A+CTE](4)-GAPDH revealed that Arg-77, which is essential for coenzyme specificity and high NADPH-dependent activity, fails to interact with NADP in these kinetically inhibited GAPDH tetramers and is attracted instead by negative residues of oxidized CTE. Other subtle changes in catalytic domains and overall conformation of the tetramers were noticed in oxidized A(2)B(2)-GAPDH and [A+CTE](4)-GAPDH, compared with fully active A(4)-GAPDH. The CTE is envisioned as a redox-sensitive regulatory domain that can force AB-GAPDH into a kinetically inhibited conformation under oxidizing conditions, which also occur during dark inactivation of the enzyme in vivo.

Molecular mechanism of thioredoxin regulation in photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase.,Fermani S, Sparla F, Falini G, Martelli PL, Casadio R, Pupillo P, Ripamonti A, Trost P Proc Natl Acad Sci U S A. 2007 Jun 26;104(26):11109-14. Epub 2007 Jun 15. PMID:17573533<ref>PMID:17573533</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 2pkr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aldehyde dehydrogenase 3D structures|Aldehyde dehydrogenase 3D structures]]
*[[Glyceraldehyde-3-phosphate dehydrogenase 3D structures|Glyceraldehyde-3-phosphate dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Spinacia oleracea]]
[[Category: Falini G]]
[[Category: Fermani S]]
[[Category: Ripamonti A]]