2VT3

Structure and functional properties of the Bacillus subtilis transcriptional repressor Rex

2VT3 の概要

• エントリーDOI: 10.2210/pdb2vt3/pdb
• 関連するPDBエントリー: 2VT2
• 分子名称: REDOX-SENSING TRANSCRIPTIONAL REPRESSOR REX, ADENOSINE-5'-TRIPHOSPHATE (3 entities in total)
• 機能のキーワード: transcriptional regulation, redox poise, transcription
• 由来する生物種: BACILLUS SUBTILIS
• 細胞内の位置: Cytoplasm : O05521
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 49259.46

構造登録者

Wang, E.,Bauer, M.C.,Rogstam, A.,Linse, S.,Logan, D.,von Wachenfeldt, C. (登録日: 2008-05-08, 公開日: 2008-09-09, 最終更新日: 2023-12-13)

主引用文献

Wang, E.,Bauer, M.C.,Rogstam, A.,Linse, S.,Logan, D.T.,von Wachenfeldt, C.
Structure and functional properties of the Bacillus subtilis transcriptional repressor Rex.
Mol. Microbiol., 69:466-478, 2008

PubMed Abstract: 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.

PubMed: 18485070
DOI: 10.1111/j.1365-2958.2008.06295.x

実験手法

X-RAY DIFFRACTION (2 Å)