3HFX

Crystal structure of carnitine transporter

3HFX の概要

• エントリーDOI: 10.2210/pdb3hfx/pdb
• 分子名称: L-carnitine/gamma-butyrobetaine antiporter, MERCURY (II) ION, CARNITINE (3 entities in total)
• 機能のキーワード: helix-turn-helix, antiport, cell inner membrane, cell membrane, transmembrane, transport, transport protein
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein: P31553
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 59076.99

構造登録者

Tang, L.,Wang, W.-H.,Bai, L.,Jiang, T. (登録日: 2009-05-13, 公開日: 2010-03-31, 最終更新日: 2024-03-20)

主引用文献

Tang, L.,Bai, L.,Wang, W.-H.,Jiang, T.
Crystal structure of the carnitine transporter and insights into the antiport mechanism
Nat.Struct.Mol.Biol., 17:492-496, 2010

PubMed Abstract: CaiT is a membrane antiporter that catalyzes the exchange of L-carnitine with gamma-butyrobetaine across the Escherichia coli membrane. To obtain structural insights into the antiport mechanism, we solved the crystal structure of CaiT at a resolution of 3.15 A. We crystallized CaiT as a homotrimer complex, in which each protomer contained 12 transmembrane helices and 4 l-carnitine molecules outlining the transport pathway across the membrane. Mutagenesis studies revealed a primary binding site at the center of the protein and a secondary substrate-binding site at the bottom of the intracellular vestibule. These results, together with the insights obtained from structural comparison with structurally homologous transporters, provide mechanistic insights into the association between substrate translocation and the conformational changes of CaiT.

PubMed: 20357772
DOI: 10.1038/nsmb.1788

実験手法

X-RAY DIFFRACTION (3.15 Å)