1h2s
From Proteopedia
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MOLECULAR BASIS OF TRANSMENBRANE SIGNALLING BY SENSORY RHODOPSIN II-TRANSDUCER COMPLEX
Overview
Microbial rhodopsins, which constitute a family of seven-helix membrane, proteins with retinal as a prosthetic group, are distributed throughout, the Bacteria, Archaea and Eukaryota. This family of photoactive proteins, uses a common structural design for two distinct functions: light-driven, ion transport and phototaxis. The sensors activate a signal transduction, chain similar to that of the two-component system of eubacterial, chemotaxis. The link between the photoreceptor and the following, cytoplasmic signal cascade is formed by a transducer molecule that binds, tightly and specifically to its cognate receptor by means of two, transmembrane helices (TM1 and TM2). It is thought that light excitation, of sensory rhodopsin II from Natronobacterium pharaonis (SRII) in complex, with its transducer (HtrII) induces an outward movement of its helix F, (ref. 6), which in turn triggers a rotation of TM2 (ref. 7). It is unclear, how this TM2 transition is converted into a cellular signal. Here we, present the X-ray structure of the complex between N. pharaonis SRII and, the receptor-binding domain of HtrII at 1.94 A resolution, which provides, an atomic picture of the first signal transduction step. Our results, provide evidence for a common mechanism for this process in phototaxis and, chemotaxis.
About this Structure
1H2S is a Protein complex structure of sequences from Natronomonas pharaonis with BOG and RET as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Molecular basis of transmembrane signalling by sensory rhodopsin II-transducer complex., Gordeliy VI, Labahn J, Moukhametzianov R, Efremov R, Granzin J, Schlesinger R, Buldt G, Savopol T, Scheidig AJ, Klare JP, Engelhard M, Nature. 2002 Oct 3;419(6906):484-7. PMID:12368857
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