4R8H

The role of protein-ligand contacts in allosteric regulation of the Escherichia coli Catabolite Activator Protein

4R8H の概要

• エントリーDOI: 10.2210/pdb4r8h/pdb
• 分子名称: cAMP-activated global transcriptional regulator CRP, 6-(6-AMINO-PURIN-9-YL)-2-THIOXO-TETRAHYDRO-2-FURO[3,2-D][1,3,2]DIOXAPHOSPHININE-2,7-DIOL, GLYCEROL, ... (4 entities in total)
• 機能のキーワード: transcription factor, transcription
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 52181.70

構造登録者

Townsend, P.D.,Pohl, E.,McLeish, T.C.B.,Rodgers, T.L.,Glover, L.C.,Korhonen, H.J.,Wilson, M.R.,Hodgson, D.R.W.,Cann, M.J. (登録日: 2014-09-02, 公開日: 2015-07-22, 最終更新日: 2024-02-28)

主引用文献

Townsend, P.D.,Rodgers, T.L.,Glover, L.C.,Korhonen, H.J.,Richards, S.A.,Colwell, L.J.,Pohl, E.,Wilson, M.R.,Hodgson, D.R.,McLeish, T.C.,Cann, M.J.
The Role of Protein-Ligand Contacts in Allosteric Regulation of the Escherichia coli Catabolite Activator Protein.
J.Biol.Chem., 290:22225-22235, 2015

PubMed Abstract: Allostery is a fundamental process by which ligand binding to a protein alters its activity at a distant site. Both experimental and theoretical evidence demonstrate that allostery can be communicated through altered slow relaxation protein dynamics without conformational change. The catabolite activator protein (CAP) of Escherichia coli is an exemplar for the analysis of such entropically driven allostery. Negative allostery in CAP occurs between identical cAMP binding sites. Changes to the cAMP-binding pocket can therefore impact the allosteric properties of CAP. Here we demonstrate, through a combination of coarse-grained modeling, isothermal calorimetry, and structural analysis, that decreasing the affinity of CAP for cAMP enhances negative cooperativity through an entropic penalty for ligand binding. The use of variant cAMP ligands indicates the data are not explained by structural heterogeneity between protein mutants. We observe computationally that altered interaction strength between CAP and cAMP variously modifies the change in allosteric cooperativity due to second site CAP mutations. As the degree of correlated motion between the cAMP-contacting site and a second site on CAP increases, there is a tendency for computed double mutations at these sites to drive CAP toward noncooperativity. Naturally occurring pairs of covarying residues in CAP do not display this tendency, suggesting a selection pressure to fine tune allostery on changes to the CAP ligand-binding pocket without a drive to a noncooperative state. In general, we hypothesize an evolutionary selection pressure to retain slow relaxation dynamics-induced allostery in proteins in which evolution of the ligand-binding site is occurring.

PubMed: 26187469
DOI: 10.1074/jbc.M115.669267

実験手法

X-RAY DIFFRACTION (1.46 Å)