Pharaonis phoborhodopsin binds to its cognate truncated transducer even in the presence of a detergent with a 1:1 stoichiometry

Yuki Sudo, Masayuki Iwamoto, Kazumi Shimono, Naoki Kamo

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)

Abstract

Pharaonis phoborhodopsin (ppR) (also pharaonis sensory rhodopsin II) is a receptor of the negative phototaxis of Natronobacterium pharaonis. ppR forms a complex with its pharaonis halobacterial transducer (pHtrII), and this complex transmits the light signal to the sensory system in the cytoplasm. The expressed C-terminal-His tagged ppR and C-terminal-His tagged truncated pHtrII (t-Htr) in Escherichia coli (His means the 6x histidine tag) form a complex even in the presence of 0.1% of n-dodecyl-β-D-maltoside, and the M-decay of the complex became about twice slower than that of ppR alone. The photocycling rates under varying concentration ratios of ppR to t-Htr in the presence of detergent were measured. The data were analyzed on the following assumptions: (1) the M-decay of both ppR alone and the complex followed a single exponential decay with different time constants; and (2) the M-decay under varying concentration ratios of ppR to t-Htr, therefore, followed a biexponential decay function which combined the decay of the free ppR and that of the complex as photoreactive species. From these analyses we estimated the dissociation constant (15.2 ± 1.8 μM) and the number of binding sites (1.2 ± 0.08).

Original languageEnglish
Pages (from-to)489-494
Number of pages6
JournalPhotochemistry and Photobiology
Volume74
Issue number3
DOIs
Publication statusPublished - Sep 1 2001
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Pharaonis phoborhodopsin binds to its cognate truncated transducer even in the presence of a detergent with a 1:1 stoichiometry'. Together they form a unique fingerprint.

Cite this