2F7C

CatM effector binding domain with its effector cis,cis-muconate

2F7C の概要

• エントリーDOI: 10.2210/pdb2f7c/pdb
• 関連するPDBエントリー: 2F6G 2F6P 2F78 2F7A 2F7B 2F8D 2F97
• 分子名称: HTH-type transcriptional regulator catM, SULFATE ION, (2Z,4Z)-HEXA-2,4-DIENEDIOIC ACID, ... (4 entities in total)
• 機能のキーワード: lttr, lysr-type transcriptional regulator, inducer binding domain, effector binding domain, muconate, gene regulation
• 由来する生物種: Acinetobacter baylyi
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26450.82

構造登録者

Clark, T.,Haddad, S.,Ezezika, O.,Neidle, E.,Momany, C. (登録日: 2005-11-30, 公開日: 2006-10-31, 最終更新日: 2023-08-23)

主引用文献

Ezezika, O.C.,Haddad, S.,Clark, T.J.,Neidle, E.L.,Momany, C.
Distinct Effector-binding Sites Enable Synergistic Transcriptional Activation by BenM, a LysR-type Regulator.
J.Mol.Biol., 367:616-629, 2007

PubMed Abstract: BenM, a bacterial transcriptional regulator, responds synergistically to two effectors, benzoate and cis,cis-muconate. CatM, a paralog with overlapping function, responds only to muconate. Structures of their effector-binding domains revealed two effector-binding sites in BenM. BenM and CatM are the first LysR-type regulators to be structurally characterized while bound with physiologically relevant exogenous inducers. The effector complexes were obtained by soaking crystals with stabilizing solutions containing high effector concentrations and minimal amounts of competing ions. This strategy, including data collection with fragments of fractured crystals, may be generally applicable to related proteins. In BenM and CatM, the binding of muconate to an interdomain pocket was facilitated by helix dipoles that provide charge stabilization. In BenM, benzoate also bound in an adjacent hydrophobic region where it alters the effect of muconate bound in the primary site. A charge relay system within the BenM protein appears to underlie synergistic transcriptional activation. According to this model, Glu162 is a pivotal residue that forms salt-bridges with different arginine residues depending on the occupancy of the secondary effector-binding site. Glu162 interacts with Arg160 in the absence of benzoate and with Arg146 when benzoate is bound. This latter interaction enhances the negative charge of muconate bound to the adjacent primary effector-binding site. The redistribution of the electrostatic potential draws two domains of the protein more closely towards muconate, with the movement mediated by the dipole moments of four alpha helices. Therefore, with both effectors, BenM achieves a unique conformation capable of high level transcriptional activation.

PubMed: 17291527
DOI: 10.1016/j.jmb.2006.09.090

実験手法

X-RAY DIFFRACTION (2.162 Å)