4RJX

Crystal structure of the OprO mutant protein F62Y/D114Y

4RJX の概要

• エントリーDOI: 10.2210/pdb4rjx/pdb
• 関連するPDBエントリー: 4RJW
• 分子名称: Porin O, (HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE, PHOSPHATE ION, ... (4 entities in total)
• 機能のキーワード: beta barrel, outer membrane protein, polyphosphate uptake channel, membrane protein
• 由来する生物種: Pseudomonas aeruginosa
• 細胞内の位置: Cell outer membrane; Multi-pass membrane protein: P32977
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 48674.44

構造登録者

van den Berg, B. (登録日: 2014-10-11, 公開日: 2015-10-21, 最終更新日: 2024-02-28)

主引用文献

Modi, N.,Ganguly, S.,Barcena-Uribarri, I.,Benz, R.,van den Berg, B.,Kleinekathofer, U.
Structure, Dynamics, and Substrate Specificity of the OprO Porin from Pseudomonas aeruginosa.
Biophys.J., 109:1429-1438, 2015

PubMed Abstract: The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier between cell and environment. For nutrient acquisition, the OM contains a number of channels that mediate uptake of small molecules by diffusion. Many of these channels are specific, i.e., they prefer certain substrates over others. In electrophysiological experiments, the OM channels OprP and OprO from Pseudomonas aeruginosa show a specificity for phosphate and diphosphate, respectively. In this study we use x-ray crystallography, free-energy molecular dynamics (MD) simulations, and electrophysiology to uncover the atomic basis for the different substrate specificity of these highly similar channels. A structural analysis of OprP and OprO revealed two crucial differences in the central constriction region. In OprP there are two tyrosine residues, Y62 and Y114, whereas the corresponding residues in OprO are phenylalanine F62 and aspartate D114. To probe the importance of these two residues in generating the different substrate specificities, the double mutants were generated in silico and in vitro. Applied-field MD simulations and electrophysiological experiments demonstrated that the double mutations interchange the phosphate and diphosphate specificities of OprP and OprO. Our findings outline a possible strategy to rationally design channel specificity by modification of a small number of residues that may be applicable to other pores as well.

PubMed: 26445443
DOI: 10.1016/j.bpj.2015.07.035

実験手法

X-RAY DIFFRACTION (1.54 Å)