1QYN

Crystal Structure of SecB from Escherichia coli

1QYN の概要

• エントリーDOI: 10.2210/pdb1qyn/pdb
• 分子名称: Protein-export protein secB (2 entities in total)
• 機能のキーワード: tetramer, greek key beta sheet, chaperone
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 68404.39

構造登録者

Dekker, C.,de Kruijff, B.,Gros, P. (登録日: 2003-09-11, 公開日: 2003-12-09, 最終更新日: 2023-08-23)

主引用文献

Dekker, C.,de Kruijff, B.,Gros, P.
Crystal structure of SecB from Escherichia coli
J.Struct.Biol., 144:313-319, 2003

PubMed Abstract: The chaperone SecB from Escherichia coli is primarily involved in passing precursor proteins into the Sec system via specific interactions with SecA. The crystal structure of SecB from E. coli has been solved to 2.35 A resolution. The structure shows flexibility in the crossover loop and the helix-connecting loop, regions that have been implicated to be part of the SecB substrate-binding site. Moreover conformational variability of Trp36 is observed as well as different loop conformations for the different monomers. Based on this, we speculate that SecB can regulate the access or extent of its hydrophobic substrate-binding site, by modulating the conformation of the crossover loop and the helix-connecting loop. The structure also clearly explains why the tetrameric equilibrium is shifted towards the dimeric state in the mutant SecBCys76Tyr. The buried cysteine residue is crucial for tight packing, and mutations are likely to disrupt the tetramer formation but not the dimer formation.

PubMed: 14643199
DOI: 10.1016/j.jsb.2003.09.012

実験手法

X-RAY DIFFRACTION (2.35 Å)