4aff: Difference between revisions

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-[[Image:4aff.png|left|200px]]
-{{STRUCTURE_4aff|  PDB=4aff  |  SCENE=  }}
+==High resolution structure of a PII mutant (I86N) protein in complex with ATP, MG and FLC==
+<StructureSection load='4aff' size='340' side='right'caption='[[4aff]], [[Resolution|resolution]] 1.05&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[4aff]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechococcus_elongatus Synechococcus elongatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AFF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AFF 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]] 1.05&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=FLC:CITRATE+ANION'>FLC</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=4aff FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aff OCA], [https://pdbe.org/4aff PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4aff RCSB], [https://www.ebi.ac.uk/pdbsum/4aff PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4aff ProSAT]</span></td></tr>
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/GLNB_SYNE7 GLNB_SYNE7] P-II indirectly controls the transcription of the GS gene (glnA). P-II prevents NR-II-catalyzed conversion of NR-I to NR-I-phosphate, the transcriptional activator of glnA. When P-II is phosphorylated, these events are reversed. In nitrogen-limiting conditions, when the ratio of Gln to 2-ketoglutarate decreases, P-II is phosphorylated which allows the deadenylation of glutamine synthetase (GS), thus activating the enzyme.
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+PII proteins are central signal processing units for the regulation of nitrogen metabolism in bacteria, archaea and plants. They act in response to cellular energy, carbon and nitrogen availability. The central metabolites ATP, ADP and 2-oxoglutarate, which indicate cellular energy and carbon/nitrogen abundance, bind in a highly organized manner to PII and induce effector-molecule-dependent conformational states of the T-loop. Depending on these states, PII proteins bind and modulate the activity of various regulatory targets. A mutant variant of the Synechococcus elongatus PII protein (PII-I86N) has been identified to have impaired 2-oxoglutarate binding. Here, the PII-I86N variant was cocrystallized in the presence of ATP, magnesium and citrate and its structure was solved at a resolution of 1.05 A. The PII-I86N variant bound citrate in place of 2-oxoglutarate. Citrate binding is mediated primarily by interactions with the ATP-coordinated magnesium ion and the backbone atoms of the T-loop. Citrate binding rearranges the conformation of the T-loop and, consistent with this, citrate suppresses the binding of PII-I86N to an NAG kinase variant, which is similar to the suppression of PII-NAG kinase complex formation by 2-OG. Based on the structures of 2-OG and citrate, homocitrate was suggested as a third ligand and an efficient response towards this molecule with different functional properties was observed. Together, these data provide a first glimpse of a genetically engineered PII variant that senses a new effector molecule.
-===High resolution structure of a PII mutant (I86N) protein in complex with ATP, MG and FLC===
+An engineered PII protein variant that senses a novel ligand: atomic resolution structure of the complex with citrate.,Zeth K, Fokina O, Forchhammer K Acta Crystallogr D Biol Crystallogr. 2012 Aug;68(Pt 8):901-8. Epub 2012 Jul 17. PMID:22868755<ref>PMID:22868755</ref>
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-==About this Structure==
+</div>
-[[4aff]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Synechococcus_elongatus Synechococcus elongatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AFF OCA].
+<div class="pdbe-citations 4aff" style="background-color:#fffaf0;"></div>
+== References ==
+<references/>
+__TOC__
+</StructureSection>
+[[Category: Large Structures]]
 [[Category: Synechococcus elongatus]]
-[[Category: Chellamuthu, V R.]]
+[[Category: Chellamuthu VR]]
-[[Category: Fokina, O.]]
+[[Category: Fokina O]]
-[[Category: Forchhammer, K.]]
+[[Category: Forchhammer K]]
-[[Category: Zeth, K.]]
+[[Category: Zeth K]]
-[[Category: Signaling protein]]