4TQV

Crystal structure of a bacterial ABC transporter involved in the import of the acidic polysaccharide alginate

4TQV の概要

• エントリーDOI: 10.2210/pdb4tqv/pdb
• 関連するPDBエントリー: 4TQU
• 分子名称: AlgM1, AlgM2, AlgS (3 entities in total)
• 機能のキーワード: abc, sphingomonas, alginate, transporter, transport protein
• 由来する生物種: Sphingomonas sp.; 詳細
• タンパク質・核酸の鎖数: 16
• 化学式量合計: 591728.66

構造登録者

Maruyama, Y.,Itoh, T.,Kaneko, A.,Nishitani, Y.,Mikami, B.,Hashimoto, W.,Murata, K. (登録日: 2014-06-12, 公開日: 2015-07-22, 最終更新日: 2024-03-20)

主引用文献

Maruyama, Y.,Itoh, T.,Kaneko, A.,Nishitani, Y.,Mikami, B.,Hashimoto, W.,Murata, K.
Structure of a Bacterial ABC Transporter Involved in the Import of an Acidic Polysaccharide Alginate
Structure, 23:1643-1654, 2015

PubMed Abstract: The acidic polysaccharide alginate represents a promising marine biomass for the microbial production of biofuels, although the molecular and structural characteristics of alginate transporters remain to be clarified. In Sphingomonas sp. A1, the ATP-binding cassette transporter AlgM1M2SS is responsible for the import of alginate across the cytoplasmic membrane. Here, we present the substrate-transport characteristics and quaternary structure of AlgM1M2SS. The addition of poly- or oligoalginate enhanced the ATPase activity of reconstituted AlgM1M2SS coupled with one of the periplasmic solute-binding proteins, AlgQ1 or AlgQ2. External fluorescence-labeled oligoalginates were specifically imported into AlgM1M2SS-containing proteoliposomes in the presence of AlgQ2, ATP, and Mg(2+). The crystal structure of AlgQ2-bound AlgM1M2SS adopts an inward-facing conformation. The interaction between AlgQ2 and AlgM1M2SS induces the formation of an alginate-binding tunnel-like structure accessible to the solvent. The translocation route inside the transmembrane domains contains charged residues suitable for the import of acidic saccharides.

PubMed: 26235029
DOI: 10.1016/j.str.2015.06.021

実験手法

X-RAY DIFFRACTION (4.504 Å)