4L4W

Structure of EspG3 chaperone from the type VII (ESX-3) secretion system

4L4W の概要

• エントリーDOI: 10.2210/pdb4l4w/pdb
• 関連するPDBエントリー: 4KXR 4RCL 5SXL
• 分子名称: EspG3 (2 entities in total)
• 機能のキーワード: esx-3, type vii secretion system, rv0289, protein secretion, chaperone, pe5-ppe4, protein transport
• 由来する生物種: Mycobacterium smegmatis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 64202.76

構造登録者

Korotkov, K.V. (登録日: 2013-06-09, 公開日: 2014-06-11, 最終更新日: 2024-11-20)

主引用文献

Tuukkanen, A.T.,Freire, D.,Chan, S.,Arbing, M.A.,Reed, R.W.,Evans, T.J.,Zenkeviciute, G.,Kim, J.,Kahng, S.,Sawaya, M.R.,Chaton, C.T.,Wilmanns, M.,Eisenberg, D.,Parret, A.H.A.,Korotkov, K.V.
Structural Variability of EspG Chaperones from Mycobacterial ESX-1, ESX-3, and ESX-5 Type VII Secretion Systems.
J. Mol. Biol., 431:289-307, 2019

PubMed Abstract: Type VII secretion systems (ESX) are responsible for transport of multiple proteins in mycobacteria. How different ESX systems achieve specific secretion of cognate substrates remains elusive. In the ESX systems, the cytoplasmic chaperone EspG forms complexes with heterodimeric PE-PPE substrates that are secreted from the cells or remain associated with the cell surface. Here we report the crystal structure of the EspG chaperone from the ESX-1 system determined using a fusion strategy with T4 lysozyme. EspG adopts a quasi 2-fold symmetric structure that consists of a central β-sheet and two α-helical bundles. In addition, we describe the structures of EspG chaperones from four different crystal forms. Alternate conformations of the putative PE-PPE binding site are revealed by comparison of the available EspG structures. Analysis of EspG, EspG, and EspG chaperones using small-angle X-ray scattering reveals that EspG and EspG chaperones form dimers in solution, which we observed in several of our crystal forms. Finally, we propose a model of the ESX-3 specific EspG-PE5-PPE4 complex based on the small-angle X-ray scattering analysis.

PubMed: 30419243
DOI: 10.1016/j.jmb.2018.11.003

実験手法

X-RAY DIFFRACTION (2.036 Å)