2vt2

Structure and functional properties of the Bacillus subtilis transcriptional repressor Rex

spinqualitylabelsall models 2vt2, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2vt2 is a 2 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.3Å Ligands: NAD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function REX_BACSU Modulates transcription in response to changes in cellular NADH/NAD(+) redox state (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The transcription factor Rex has been implicated in regulation of the expression of genes important for fermentative growth and for growth under conditions of low oxygen tension in several Gram-positive bacteria. Rex senses the redox poise of the cell through changes in the NADH/NAD(+) ratio. The crystal structures of two essentially identical Rex proteins, from Thermus aquaticus and T. thermophilus, have previously been determined in complex with NADH. Here we present the crystal structure of the Rex protein from Bacillus subtilis, as well as extensive studies of its affinity for nucleotides and DNA, using surface plasmon resonance, isothermal titration calorimetry and electrophoretic mobility shift assays. We show that Rex has a very high affinity for NADH but that its affinity for NAD(+) is 20 000 times lower. However, the NAD(+) affinity is increased by a factor of 30 upon DNA binding, suggesting that there is a positive allosteric coupling between DNA binding and NAD(+) binding. The crystal structures of two pseudo-apo forms (from crystals soaked with NADH and cocrystallized with ATP) show a very different conformation from the previously determined Rex:NADH complexes, in which the N-terminal domains are splayed away from the dimer core. A mechanism is proposed whereby conformational changes in a C-terminal domain-swapped helix mediate the transition from a flexible DNA binding form to a locked NADH-bound form incapable of binding DNA. Structure and functional properties of the Bacillus subtilis transcriptional repressor Rex.,Wang E, Bauer MC, Rogstam A, Linse S, Logan DT, von Wachenfeldt C Mol Microbiol. 2008 Jul;69(2):466-78. PMID:18485070 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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