6ST0

Taurine ABC transporter substrate binding protein TauA from E. coli in complex with N-(2-Acetamido)-2-aminoethanesulfonic acid

6ST0 の概要

• エントリーDOI: 10.2210/pdb6st0/pdb
• 分子名称: Taurine-binding periplasmic protein, IODIDE ION, N-(2-acetamido)-2-aminoethanesulfonic acid, ... (4 entities in total)
• 機能のキーワード: taurine substrate binding protein, abc transporter, transport protein
• 由来する生物種: Escherichia coli (strain K12)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 65654.08

構造登録者

Beis, K.,Qu, F. (登録日: 2019-09-09, 公開日: 2019-12-18, 最終更新日: 2024-01-24)

主引用文献

Qu, F.,ElOmari, K.,Wagner, A.,De Simone, A.,Beis, K.
Desolvation of the substrate-binding protein TauA dictates ligand specificity for the alkanesulfonate ABC importer TauABC.
Biochem.J., 476:3649-3660, 2019

PubMed Abstract: Under limiting sulfur availability, bacteria can assimilate sulfur from alkanesulfonates. Bacteria utilize ATP-binding cassette (ABC) transporters to internalise them for further processing to release sulfur. In gram-negative bacteria the TauABC and SsuABC ensure internalization, although, these two systems have common substrates, the former has been characterized as a taurine specific system. TauA and SsuA are substrate-binding proteins (SBPs) that bind and bring the alkanesulfonates to the ABC importer for transport. Here, we have determined the crystal structure of TauA and have characterized its thermodynamic binding parameters by isothermal titration calorimetry in complex with taurine and different alkanesulfonates. Our structures revealed that the coordination of the alkanesulfonates is conserved, with the exception of Asp205 that is absent from SsuA, but the thermodynamic parameters revealed a very high enthalpic penalty cost for binding of the other alkanesulfonates relative to taurine. Our molecular dynamic simulations indicated that the different levels of hydration of the binding site contributed to the selectivity for taurine over the other alkanesulfonates. Such selectivity mechanism is very likely to be employed by other SBPs of ABC transporters.

PubMed: 31802112
DOI: 10.1042/BCJ20190779

実験手法

X-RAY DIFFRACTION (1.5 Å)