6TZK

Bacterial cellulose synthase outermembrane channel BcsC with terminal TPR repeat

6TZK の概要

• エントリーDOI: 10.2210/pdb6tzk/pdb
• 分子名称: Cellulose synthase operon protein C, DODECYL-BETA-D-MALTOSIDE, HEXANE-1,6-DIOL, ... (8 entities in total)
• 機能のキーワード: porin, polysaccharide secretion, cellulose synthase, membrane protein
• 由来する生物種: Escherichia coli K-12
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 52511.04

構造登録者

Acheson, J.F.,Derewenda, Z.,Zimmer, J. (登録日: 2019-08-12, 公開日: 2019-10-23, 最終更新日: 2024-11-13)

主引用文献

Acheson, J.F.,Derewenda, Z.S.,Zimmer, J.
Architecture of the Cellulose Synthase Outer Membrane Channel and Its Association with the Periplasmic TPR Domain.
Structure, 27:1855-, 2019

PubMed Abstract: Extracellular bacterial cellulose contributes to biofilm stability and to the integrity of the bacterial cell envelope. In Gram-negative bacteria, cellulose is synthesized and secreted by a multi-component cellulose synthase complex. The BcsA subunit synthesizes cellulose and also transports the polymer across the inner membrane. Translocation across the outer membrane occurs through the BcsC porin, which extends into the periplasm via 19 tetra-tricopeptide repeats (TPR). We present the crystal structure of a truncated BcsC, encompassing the last TPR repeat and the complete outer membrane channel domain, revealing a 16-stranded, β barrel pore architecture. The pore is blocked by an extracellular gating loop, while the extended C terminus inserts deeply into the channel and positions a conserved Trp residue near its extracellular exit. The channel is lined with hydrophilic and aromatic residues suggesting a mechanism for facilitated cellulose diffusion based on aromatic stacking and hydrogen bonding.

PubMed: 31604608
DOI: 10.1016/j.str.2019.09.008

実験手法

X-RAY DIFFRACTION (1.852 Å)