4R22
TnrA-DNA complex
Summary for 4R22
Entry DOI | 10.2210/pdb4r22/pdb |
Related | 4R24 4R25 |
Descriptor | HTH-type transcriptional regulator TnrA, DNA (5'-D(*CP*GP*TP*GP*TP*AP*AP*GP*GP*AP*AP*TP*TP*CP*TP*GP*AP*CP*AP*CP*G)-3') (2 entities in total) |
Functional Keywords | new family of transcription regulators, transcription, gs, transcription-dna complex, transcription/dna |
Biological source | Bacillus megaterium More |
Total number of polymer chains | 2 |
Total formula weight | 16195.33 |
Authors | Schumacher, M.A. (deposition date: 2014-08-08, release date: 2015-03-04, Last modification date: 2024-02-28) |
Primary citation | Schumacher, M.A.,Chinnam, N.B.,Cuthbert, B.,Tonthat, N.K.,Whitfill, T. Structures of regulatory machinery reveal novel molecular mechanisms controlling B. subtilis nitrogen homeostasis. Genes Dev., 29:451-464, 2015 Cited by PubMed Abstract: 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. PubMed: 25691471DOI: 10.1101/gad.254714.114 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.6 Å) |
Structure validation
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