7L16

Crystal structure of sugar-bound melibiose permease MelB

7L16 の概要

• エントリーDOI: 10.2210/pdb7l16/pdb
• 関連するBIRD辞書のPRD_ID: PRD_002459
• 分子名称: Melibiose carrier protein, dodecyl 6-O-alpha-D-galactopyranosyl-beta-D-glucopyranoside (2 entities in total)
• 機能のキーワード: mfs-fold, galactoside binding, secondary active transport, melb, transport protein
• 由来する生物種: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 54603.11

構造登録者

Guan, L. (登録日: 2020-12-14, 公開日: 2021-08-04, 最終更新日: 2024-05-22)

主引用文献

Guan, L.,Hariharan, P.
X-ray crystallography reveals molecular recognition mechanism for sugar binding in a melibiose transporter MelB.
Commun Biol, 4:931-931, 2021

PubMed Abstract: Major facilitator superfamily_2 transporters are widely found from bacteria to mammals. The melibiose transporter MelB, which catalyzes melibiose symport with either Na, Li, or H, is a prototype of the Na-coupled MFS transporters, but its sugar recognition mechanism has been a long-unsolved puzzle. Two high-resolution X-ray crystal structures of a Salmonella typhimurium MelB mutant with a bound ligand, either nitrophenyl-α-D-galactoside or dodecyl-β-D-melibioside, were refined to a resolution of 3.05 or 3.15 Å, respectively. In the substrate-binding site, the interaction of both galactosyl moieties on the two ligands with MelB are virturally same, so the sugar specificity determinant pocket can be recognized, and hence the molecular recognition mechanism for sugar binding in MelB has been deciphered. The conserved cation-binding pocket is also proposed, which directly connects to the sugar specificity pocket. These key structural findings have laid a solid foundation for our understanding of the cooperative binding and symport mechanisms in Na-coupled MFS transporters, including eukaryotic transporters such as MFSD2A.

PubMed: 34341464
DOI: 10.1038/s42003-021-02462-x

実験手法

X-RAY DIFFRACTION (3.15 Å)