Opposite displacement of helix F in attractant and repellent signaling by sensory rhodopsin-Htr complexes.

ABSTRACT: Two forms of the phototaxis receptor sensory rhodopsin I distinguished by differences in its photoactive site have been shown to be directly correlated with attractant and repellent signaling by the dual-signaling protein. In prior studies, differences in the photoactive site defined the two forms, namely the direction of light-induced proton transfer from the chromophore and the pK(a) of an Asp counterion to the protonated chromophore. Here, we show by both in vivo and in vitro measurements that the two forms are distinct protein conformers with structural similarities to two conformers seen in the light-driven proton transport cycle of the related protein bacteriorhodopsin. Measurements of spontaneous cell motility reversal frequencies, an in vivo measure of histidine kinase activity in

SUBMITTER: Sasaki J 

PROVIDER: S-EPMC3099703 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature