View source for 3uie


==Crystal structure of adenosine 5'-phosphosulfate kinase from Arabidopsis Thaliana in Complex with AMPPNP and APS==
<StructureSection load='3uie' size='340' side='right'caption='[[3uie]], [[Resolution|resolution]] 1.79&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3uie]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3UIE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3UIE 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]] 1.794&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADX:ADENOSINE-5-PHOSPHOSULFATE'>ADX</scene>, <scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=3uie FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3uie OCA], [https://pdbe.org/3uie PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3uie RCSB], [https://www.ebi.ac.uk/pdbsum/3uie PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3uie ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/APK1_ARATH APK1_ARATH] Catalyzes the synthesis of activated sulfate. Essential for plant reproduction and viability. Required for the production of glucosinolates.<ref>PMID:11488606</ref> <ref>PMID:19304933</ref> <ref>PMID:19903478</ref> <ref>PMID:23218016</ref> <ref>PMID:7988678</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Adenosine-5'-phosphosulfate (APS) kinase (APSK) catalyzes the phosphorylation of APS to 3'-phospho-APS (PAPS). In Arabidopsis thaliana, APSK is essential for reproductive viability and competes with APS reductase to partition sulfate between the primary and secondary branches of the sulfur assimilatory pathway; however, the biochemical regulation of APSK is poorly understood. The 1.8-A resolution crystal structure of APSR from A. thaliana (AtAPSK) in complex with beta,gamma-imidoadenosine-5'-triphosphate, Mg(2+), and APS provides a view of the Michaelis complex for this enzyme and reveals the presence of an intersubunit disulfide bond between Cys86 and Cys119. Functional analysis of AtAPSK demonstrates that reduction of Cys86-Cys119 resulted in a 17-fold higher k(cat)/K(m) and a 15-fold increase in K(i) for substrate inhibition by APS compared with the oxidized enzyme. The C86A/C119A mutant was kinetically similar to the reduced WT enzyme. Gel- and activity-based titrations indicate that the midpoint potential of the disulfide in AtAPSK is comparable to that observed in APS reductase. Both cysteines are invariant among the APSK from plants, but not other organisms, which suggests redox-control as a unique regulatory feature of the plant APSK. Based on structural, functional, and sequence analyses, we propose that the redox-sensitive APSK evolved after bifurcation of the sulfur assimilatory pathway in the green plant lineage and that changes in redox environment resulting from oxidative stresses may affect partitioning of APS into the primary and secondary thiol metabolic routes by having opposing effects on APSK and APS reductase in plants.

Structural basis and evolution of redox regulation in plant adenosine-5'-phosphosulfate kinase.,Ravilious GE, Nguyen A, Francois JA, Jez JM Proc Natl Acad Sci U S A. 2012 Jan 3;109(1):309-14. Epub 2011 Dec 19. PMID:22184237<ref>PMID:22184237</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3uie" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Jez JM]]
[[Category: Ravilious GE]]