%0 Journal Article
%A Kriegsmann, J.
%A Brehs, M.
%A Klare, J.P.
%A Engelhard, M.
%A Fitter, J.
%T Sensory rhodopsin II/transducer complex formation in detergent and in lipid bilayers studied with FRET
%J Biochimica et biophysica acta / Biomembranes
%V 1788
%@ 0005-2736
%C Amsterdam
%I Elsevier
%M PreJuSER-5168
%P 522 - 531
%D 2009
%Z J. F. thanks G. Buldt (Forschungszentrum Julich) for continuous and sustainable support in his institute. This work was supported by the Deutsche Forschungsgerneinschaft (M.E.) and by a priority program SPP 1128 of Deutsche Forschungsgerneinschaft (FI 841/3-1,2 to J.F.). We are indebted to R. Schlesinger for providing us with bacteriorhodopsin and to R. Batra-Safferling for the discussions and comments on the manuscript.
%X The photophobic receptor from Natronomonas pharaonis (NpSRII) forms a photo-signalling complex with its cognate transducer (NpHtrII). In order to elucidate the complex formation in more detail, we have studied the intermolecular binding of both constituents (NpSRII and NpHtrII157; truncated at residue 157) in detergent buffers, and in lipid bilayers using FRET. The data for hetero-dimer formation of NpSRII/NpHtrII in detergent agrees well with KD values (approximately 200 nM) described in the literature. In lipid bilayers, the binding affinity between proteins in the NpSRII/NpHtrII complex is at least one order of magnitude stronger. In detergent the strength of binding is similar for both homo-dimers (NpSRII/NpSRII and NpHtrII/NpHtrII) but significantly weaker (KD approximately 16 microM) when compared to the hetero-dimer. The intermolecular binding is again considerably stronger in lipid bilayers; however, it is not as strong as that observed for the hetero-dimer. At a molar transducer/lipid ratio of 1:2000, which is still well above physiological concentrations, only 40% homo-dimers are formed. Apparently, in cell membranes the formation of the assumed functionally active oligomeric 2:2 complex depends on the full-length transducer including the helical cytoplasmic part, which is thought to tighten the transducer-dimer association.
%K Archaeal Proteins: chemistry
%K Archaeal Proteins: genetics
%K Archaeal Proteins: metabolism
%K Biophysical Phenomena
%K Detergents
%K Halobacteriaceae: chemistry
%K Halobacteriaceae: genetics
%K Halobacteriaceae: metabolism
%K Lipid Bilayers: chemistry
%K Models, Molecular
%K Protein Binding
%K Protein Multimerization
%K Protein Structure, Quaternary
%K Sensory Rhodopsins: chemistry
%K Sensory Rhodopsins: genetics
%K Sensory Rhodopsins: metabolism
%K Signal Transduction
%K Spectrophotometry
%K Archaeal Proteins (NLM Chemicals)
%K Detergents (NLM Chemicals)
%K HtrII protein, Natronobacterium pharaonis (NLM Chemicals)
%K Lipid Bilayers (NLM Chemicals)
%K Sensory Rhodopsins (NLM Chemicals)
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:19094962
%U <Go to ISI:>//WOS:000263794700025
%R 10.1016/j.bbamem.2008.11.011
%U https://juser.fz-juelich.de/record/5168