%0 Journal Article
%A Budyak, I. L.
%A Pipich, V.
%A Mironova, O. S.
%A Schlesinger, R.
%A Zaccai, G.
%A Klein-Seetharaman, J.
%T Shape and oligomerization state of the cytoplasmic domain of the phototaxis transducer II from Natronobacterium pharaonis
%J Proceedings of the National Academy of Sciences of the United States of America
%V 103
%@ 0027-8424
%C Washington, DC
%I Academy
%M PreJuSER-53707
%P 15428 - 15433
%D 2006
%Z Record converted from VDB: 12.11.2012
%X Phototaxis allows archaea to adjust flagellar motion in response to light. In the photophobic response of Natronobacterium pharaonis, light-activated sensory rhodopsin II causes conformational changes in the transducer II protein (pHtrII), initiating the two-component signaling system analogous to bacterial chemotaxis. pHtrII's cytoplasmic domain (pHtrII-cyt) is homologous to the cytoplasmic domains of eubacterial chemotaxis receptors. Chemotaxis receptors require dimerization for activity and are in vivo-organized in large clusters. In this study we investigated the oligomerization and aggregation states of pHtrII-cyt by using chemical cross-linking, analytical gel-filtration chromatography, and small-angle neutron scattering. We show that pHtrII-cyt is monomeric in dilute buffers, but forms dimers in 4 M KCl, the physiological salt concentration for halophilic archaea. At high ammonium sulfate concentration, the protein forms higher-order aggregates. The monomeric protein has a rod-like shape, 202 A in length and 14.4 A in diameter; upon dimerization the length increases to 248 A and the diameter to 18.2 A. These results suggest that under high salt concentration the shape and oligomerization state of pHtrII-cyt are comparable to those of chemotaxis receptors.
%K Archaeal Proteins: chemistry
%K Archaeal Proteins: genetics
%K Archaeal Proteins: metabolism
%K Biopolymers: chemistry
%K Carotenoids: chemistry
%K Carotenoids: genetics
%K Carotenoids: metabolism
%K Cross-Linking Reagents: chemistry
%K Crystallography, X-Ray
%K Dimerization
%K Light
%K Natronobacterium: chemistry
%K Natronobacterium: metabolism
%K Particle Size
%K Phototrophic Processes: physiology
%K Protein Structure, Quaternary
%K Protein Structure, Tertiary
%K Archaeal Proteins (NLM Chemicals)
%K Biopolymers (NLM Chemicals)
%K Cross-Linking Reagents (NLM Chemicals)
%K phototaxis receptor sensory rhodopsin II, Natronobacterium pharaonis (NLM Chemicals)
%K Carotenoids (NLM Chemicals)
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:17032755
%2 pmc:PMC1592645
%U <Go to ISI:>//WOS:000241476200029
%R 10.1073/pnas.0607201103
%U https://juser.fz-juelich.de/record/53707