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Dynamic structure of pharaonis phoborhodopsin (sensory rhodopsin II) and complex with a cognate truncated transducer as revealed by site‐directed 13 C solid‐state NMR
Author(s) -
Arakawa Tadashi,
Shimono Kazumi,
Yamaguchi Satoru,
Tuzi Satoru,
Sudo Yuki,
Kamo Naoki,
Saitô Hazime
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00065-6
Subject(s) - bacteriorhodopsin , chemistry , rhodopsin , helix (gastropod) , crystallography , nuclear magnetic resonance spectroscopy , transmembrane domain , transmembrane protein , solid state nuclear magnetic resonance , stereochemistry , nuclear magnetic resonance , membrane , physics , biology , biochemistry , retinal , ecology , receptor , snail
We have recorded 13 C nuclear magnetic resonance (NMR) spectra of [3‐ 13 C]Ala, [1‐ 13 C]Val‐labeled pharaonis phoborhodopsin ( p pR or sensory rhodopsin II) incorporated into egg PC (phosphatidylcholine) bilayer, by means of site‐directed high‐resolution solid‐state NMR techniques. Seven 13 C NMR signals from transmembrane α‐helices were resolved for [3‐ 13 C]Ala‐ p pR at almost the same positions as those of bacteriorhodopsin (bR), except for the suppressed peaks in the loop regions in spite of the presence of at least three Ala residues. In contrast, 13 C NMR signals from the loops were visible from [1‐ 13 C]Val‐ p pR but their peak positions of the transmembrane α‐helices are not always the same between p pR and bR. The motional frequency of the loop regions in p pR was estimated as 10 5 Hz in view of the suppressed peaks from [3‐ 13 C]Ala‐ p pR due to interference with proton decoupling frequency. We found that conformation and dynamics of p pR were appreciably altered by complex formation with a cognate truncated transducer p Htr II (1–159). In particular, the C‐terminal α‐helix protruding from the membrane surface is involved in the complex formation and subsequent fluctuation frequency is reduced by one order of magnitude.