4s0r: Difference between revisions
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''' | ==Structure of GS-TnrA complex== | ||
<StructureSection load='4s0r' size='340' side='right' caption='[[4s0r]], [[Resolution|resolution]] 3.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4s0r]] is a 28 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4S0R OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4S0R FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLN:GLUTAMINE'>GLN</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glutamate--ammonia_ligase Glutamate--ammonia ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.1.2 6.3.1.2] </span></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=4s0r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4s0r OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4s0r RCSB], [http://www.ebi.ac.uk/pdbsum/4s0r PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
All cells must sense and adapt to changing nutrient availability. However, detailed molecular mechanisms coordinating such regulatory pathways remain poorly understood. In Bacillus subtilis, nitrogen homeostasis is controlled by a unique circuitry composed of the regulator TnrA, which is deactivated by feedback-inhibited glutamine synthetase (GS) during nitrogen excess and stabilized by GlnK upon nitrogen depletion, and the repressor GlnR. Here we describe a complete molecular dissection of this network. TnrA and GlnR, the global nitrogen homeostatic transcription regulators, are revealed as founders of a new structural family of dimeric DNA-binding proteins with C-terminal, flexible, effector-binding sensors that modulate their dimerization. Remarkably, the TnrA sensor domains insert into GS intersubunit catalytic pores, destabilizing the TnrA dimer and causing an unprecedented GS dodecamer-to-tetradecamer conversion, which concomitantly deactivates GS. In contrast, each subunit of the GlnK trimer "templates" active TnrA dimers. Unlike TnrA, GlnR sensors mediate an autoinhibitory dimer-destabilizing interaction alleviated by GS, which acts as a GlnR chaperone. Thus, these studies unveil heretofore unseen mechanisms by which inducible sensor domains drive metabolic reprograming in the model Gram-positive bacterium B. subtilis. | |||
Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis.,Schumacher MA, Chinnam NB, Cuthbert B, Tonthat NK, Whitfill T Genes Dev. 2015 Feb 15;29(4):451-64. doi: 10.1101/gad.254714.114. PMID:25691471<ref>PMID:25691471</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
[[Category: | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Glutamate--ammonia ligase]] | |||
[[Category: Chinnam, N G]] | |||
[[Category: Cuthbert, B]] | [[Category: Cuthbert, B]] | ||
[[Category: Schumacher, M | [[Category: Schumacher, M A]] | ||
[[Category: Tonthat, N | [[Category: Tonthat, N K]] | ||
[[Category: | [[Category: Chaperone]] | ||
[[Category: Glutamine synthesis]] | |||
[[Category: Ligase]] | |||
[[Category: Transcription regulation]] | |||
Revision as of 14:27, 4 March 2015
Structure of GS-TnrA complexStructure of GS-TnrA complex
Structural highlights
Publication Abstract from PubMedAll cells must sense and adapt to changing nutrient availability. However, detailed molecular mechanisms coordinating such regulatory pathways remain poorly understood. In Bacillus subtilis, nitrogen homeostasis is controlled by a unique circuitry composed of the regulator TnrA, which is deactivated by feedback-inhibited glutamine synthetase (GS) during nitrogen excess and stabilized by GlnK upon nitrogen depletion, and the repressor GlnR. Here we describe a complete molecular dissection of this network. TnrA and GlnR, the global nitrogen homeostatic transcription regulators, are revealed as founders of a new structural family of dimeric DNA-binding proteins with C-terminal, flexible, effector-binding sensors that modulate their dimerization. Remarkably, the TnrA sensor domains insert into GS intersubunit catalytic pores, destabilizing the TnrA dimer and causing an unprecedented GS dodecamer-to-tetradecamer conversion, which concomitantly deactivates GS. In contrast, each subunit of the GlnK trimer "templates" active TnrA dimers. Unlike TnrA, GlnR sensors mediate an autoinhibitory dimer-destabilizing interaction alleviated by GS, which acts as a GlnR chaperone. Thus, these studies unveil heretofore unseen mechanisms by which inducible sensor domains drive metabolic reprograming in the model Gram-positive bacterium B. subtilis. Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis.,Schumacher MA, Chinnam NB, Cuthbert B, Tonthat NK, Whitfill T Genes Dev. 2015 Feb 15;29(4):451-64. doi: 10.1101/gad.254714.114. PMID:25691471[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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