Transmembrane topology of the Rieske Fe/S protein of the cytochrome b6/f complex from spinach chloroplasts

FEBS Letters

Karnauchov, Ivan¹  Herrmann, Reinhold G¹  Klösgen, Ralf Bernd¹ 

[1] Botanisches Institut der Ludwig-Maximilians-Universität, Menzinger Strasse 67, D-80638 Munich, Germany

关键词: Rieske Fe/S protein;    Cytochrome b6/f complex;    Thylakoid membrane;    Chloroplast;    Photosynthesis;    Protein topology;   

DOI  :  10.1016/S0014-5793(97)00427-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The topology of the Rieske protein of the cytochrome b₆/f complex in thylakoids from spinach chloroplasts was examined by protease protection experiments as well as polypeptide extraction assays using solutions of chaotropic salts or alkaline pH. While neither thermolysin nor trypsin cleave any of the Rieske protein when added to the stromal side of the thylakoid membrane, proteinase K is capable of removing approximately four residues from its NH₂-terminus. The protein is resistant to membrane extraction by 0.1 M Na₂CO₃ or 2 M NaBr but is quantitatively released by 0.1 M NaOH. Treatment of thylakoids with 2 M NaSCN leads to extraction of variable amounts of the protein, depending on the presence or absence of sucrose in the medium which apparently stabilizes the cytochrome complex. From these results we conclude that the Rieske protein is an integral component of the cytochrome complex which spans the thylakoid membrane with a single hydrophobic segment and is anchored predominantly by electrostatic interactions.

【 授权许可】

Unknown