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| | ==Structure of wildtype PII from S. elongatus at medium resolution== | | ==Structure of wildtype PII from S. elongatus at medium resolution== |
| - | <StructureSection load='4c3m' size='340' side='right' caption='[[4c3m]], [[Resolution|resolution]] 2.15Å' scene=''> | + | <StructureSection load='4c3m' size='340' side='right'caption='[[4c3m]], [[Resolution|resolution]] 2.15Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4c3m]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Pcc_6301 Pcc 6301]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4C3M OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4C3M FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4c3m]] is a 3 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=4C3M OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4C3M FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4c3k|4c3k]], [[4c3l|4c3l]]</td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.149Å</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4c3m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4c3m OCA], [http://pdbe.org/4c3m PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4c3m RCSB], [http://www.ebi.ac.uk/pdbsum/4c3m PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4c3m ProSAT]</span></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=4c3m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4c3m OCA], [https://pdbe.org/4c3m PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4c3m RCSB], [https://www.ebi.ac.uk/pdbsum/4c3m PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4c3m ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://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. | + | [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;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Pcc 6301]] | + | [[Category: Large Structures]] |
| - | [[Category: Forchhammer, K]] | + | [[Category: Synechococcus elongatus]] |
| - | [[Category: Zeth, K]] | + | [[Category: Forchhammer K]] |
| - | [[Category: Transcription]] | + | [[Category: Zeth K]] |
| Structural highlights
Function
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.
Publication Abstract from PubMed
PII signaling proteins comprise one of the most versatile signaling devices in nature and have a highly conserved structure. In cyanobacteria, PipX and N-acetyl-L-glutamate kinase (NAGK) are receptors of PII signaling, and these interactions are modulated by ADP, ATP, and 2-oxoglutarate. These effector molecules bind interdependently to three anti-cooperative binding sites on the trimeric PII protein and thereby affect its structure. Here, we used the PII protein from Synechococcus elongatus PCC 7942 to reveal the structural basis of anti-cooperative ADP binding. Furthermore, we clarified the mutual influence of PII-receptor interaction and sensing of the ATP/ADP ratio. The crystal structures of two forms of trimeric PII - one with one ADP bound and the other with all three ADP-binding sites occupied - revealed significant differences in the ADP binding mode: at one site (S1), ADP is tightly bound through side-chain and main-chain interactions, whereas at the other two sites (S2 and S3), the ADP molecules are only bound by main-chain interactions. In the presence of the PII-receptor PipX, the affinity of ADP to the first binding site S1 strongly increases, whereas the affinity for ATP decreases owing to PipX favoring the S1 conformation of PII-ADP. In consequence, PII-PipX interaction is highly sensitive to subtle fluctuations in the ATP/ADP ratio. By contrast, the PII-NAGK interaction, which is negatively affected by ADP, is insensitive to these fluctuations. Modulation of the metabolite-sensing properties of PII by its receptors allows PII to differentially perceive signals in a target-specific manner and to perform multitasking signal transduction.
Structural Basis and Target-Specific Modulation of ADP Sensing by the Synechococcus elongatus PII Signaling Protein.,Zeth K, Fokina O, Forchhammer K J Biol Chem. 2014 Feb 11. PMID:24519945[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Zeth K, Fokina O, Forchhammer K. Structural Basis and Target-Specific Modulation of ADP Sensing by the Synechococcus elongatus PII Signaling Protein. J Biol Chem. 2014 Feb 11. PMID:24519945 doi:http://dx.doi.org/10.1074/jbc.M113.536557
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