TY  - JOUR
AU  - Budyak, I. L.
AU  - Pipich, V.
AU  - Mironova, O. S.
AU  - Schlesinger, R.
AU  - Zaccai, G.
AU  - Klein-Seetharaman, J.
TI  - Shape and oligomerization state of the cytoplasmic domain of the phototaxis transducer II from Natronobacterium pharaonis
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 103
SN  - 0027-8424
CY  - Washington, DC
PB  - Academy
M1  - PreJuSER-53707
SP  - 15428 - 15433
PY  - 2006
N1  - Record converted from VDB: 12.11.2012
AB  - 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.
KW  - Archaeal Proteins: chemistry
KW  - Archaeal Proteins: genetics
KW  - Archaeal Proteins: metabolism
KW  - Biopolymers: chemistry
KW  - Carotenoids: chemistry
KW  - Carotenoids: genetics
KW  - Carotenoids: metabolism
KW  - Cross-Linking Reagents: chemistry
KW  - Crystallography, X-Ray
KW  - Dimerization
KW  - Light
KW  - Natronobacterium: chemistry
KW  - Natronobacterium: metabolism
KW  - Particle Size
KW  - Phototrophic Processes: physiology
KW  - Protein Structure, Quaternary
KW  - Protein Structure, Tertiary
KW  - Archaeal Proteins (NLM Chemicals)
KW  - Biopolymers (NLM Chemicals)
KW  - Cross-Linking Reagents (NLM Chemicals)
KW  - phototaxis receptor sensory rhodopsin II, Natronobacterium pharaonis (NLM Chemicals)
KW  - Carotenoids (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:17032755
C2  - pmc:PMC1592645
UR  - <Go to ISI:>//WOS:000241476200029
DO  - DOI:10.1073/pnas.0607201103
UR  - https://juser.fz-juelich.de/record/53707
ER  -