1Y4E

NMR structure of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger

1Y4E の概要

• エントリーDOI: 10.2210/pdb1y4e/pdb
• NMR情報: BMRB: 6446
• 分子名称: Sodium/hydrogen exchanger 1 (1 entity in total)
• 機能のキーワード: nhe1 isoform, transmembrane, membrane protein
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Membrane; Multi-pass membrane protein: P19634
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3139.75

構造登録者

Slepkov, E.R.,Rainey, J.K.,Li, X.,Liu, Y.,Lindhout, D.A.,Sykes, B.D.,Fliegel, L. (登録日: 2004-11-30, 公開日: 2005-02-01, 最終更新日: 2022-03-02)

主引用文献

Slepkov, E.R.,Rainey, J.K.,Li, X.,Liu, Y.,Cheng, F.J.,Lindhout, D.A.,Sykes, B.D.,Fliegel, L.
Structural and functional characterization of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger.
J.Biol.Chem., 280:17863-17872, 2005

PubMed Abstract: The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals. We characterized the structural and functional aspects of the critical transmembrane (TM) segment IV. Each residue was mutated to cysteine in cysteine-less NHE1. TM IV was exquisitely sensitive to mutation with 10 of 23 mutations causing greatly reduced expression and/or activity. The Phe(161) --> Cys mutant was inhibited by treatment with the water-soluble sulfhydryl-reactive compounds [2-(trimethylammonium)ethyl]methanethiosulfonate and [2-sulfonatoethyl]methanethiosulfonate, suggesting it is a pore-lining residue. The structure of purified TM IV peptide was determined using high resolution NMR in a CD(3)OH:CDCl(3):H(2)O mixture and in Me(2)SO. In CD(3)OH: CDCl(3):H(2)O, TM IV was structured but not as a canonical alpha-helix. Residues Asp(159)-Leu(162) were a series of beta-turns; residues Leu(165)-Pro(168) showed an extended structure, and residues Ile(169)-Phe(176) were helical in character. These three structured regions rotated quite freely with respect to the others. In Me(2)SO, the structure was much less defined. Our results demonstrate that TM IV is an unusually structured transmembrane segment that is exquisitely sensitive to mutagenesis and that Phe(161) is a pore-lining residue.

PubMed: 15677483
DOI: 10.1074/jbc.M409608200

実験手法

SOLUTION NMR