3Q7T

2.15A resolution structure (I41 Form) of the ChxR receiver domain from Chlamydia trachomatis

3Q7T の概要

• エントリーDOI: 10.2210/pdb3q7t/pdb
• 関連するPDBエントリー: 3q7r 3q7s
• 分子名称: Transcriptional regulatory protein, SODIUM ION (3 entities in total)
• 機能のキーワード: chxr, receiver domain, transcription factor, ompr, chlamydia, transcription
• 由来する生物種: Chlamydia trachomatis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 28566.65

構造登録者

Hickey, J.,Lovell, S.,Battaile, K.P.,Hu, L.,Middaugh, C.R.,Hefty, P.S. (登録日: 2011-01-05, 公開日: 2011-07-20, 最終更新日: 2024-02-21)

主引用文献

Hickey, J.M.,Lovell, S.,Battaile, K.P.,Hu, L.,Middaugh, C.R.,Hefty, P.S.
The atypical response regulator protein ChxR has structural characteristics and dimer interface interactions that are unique within the OmpR/PhoB subfamily.
J.Biol.Chem., 286:32606-32616, 2011

PubMed Abstract: Typically as a result of phosphorylation, OmpR/PhoB response regulators form homodimers through a receiver domain as an integral step in transcriptional activation. Phosphorylation stabilizes the ionic and hydrophobic interactions between monomers. Recent studies have shown that some response regulators retain functional activity in the absence of phosphorylation and are termed atypical response regulators. The two currently available receiver domain structures of atypical response regulators are very similar to their phospho-accepting homologs, and their propensity to form homodimers is generally retained. An atypical response regulator, ChxR, from Chlamydia trachomatis, was previously reported to form homodimers; however, the residues critical to this interaction have not been elucidated. We hypothesize that the intra- and intermolecular interactions involved in forming a transcriptionally competent ChxR are distinct from the canonical phosphorylation (activation) paradigm in the OmpR/PhoB response regulator subfamily. To test this hypothesis, structural and functional studies were performed on the receiver domain of ChxR. Two crystal structures of the receiver domain were solved with the recently developed method using triiodo compound I3C. These structures revealed many characteristics unique to OmpR/PhoB subfamily members: typical or atypical. Included was the absence of two α-helices present in all other OmpR/PhoB response regulators. Functional studies on various dimer interface residues demonstrated that ChxR forms relatively stable homodimers through hydrophobic interactions, and disruption of these can be accomplished with the introduction of a charged residue within the dimer interface. A gel shift study with monomeric ChxR supports that dimerization through the receiver domain is critical for interaction with DNA.

PubMed: 21775428
DOI: 10.1074/jbc.M111.220574

実験手法

X-RAY DIFFRACTION (2.15 Å)