1x0s
From Proteopedia
Crystal structure of the 13-cis isomer of bacteriorhodopsin
Overview
The atomic structure of the trans isomer of bacteriorhodopsin was determined previously by using a 3D crystal belonging to the space group P622. Here, a structure is reported for another isomer with the 13-cis, 15-syn retinal in a dark-adapted crystal. Structural comparison of the two isomers indicates that retinal isomerization around the C13[double bond]C14 and the C15[double bond]N bonds is accompanied by noticeable displacements of a few residues in the vicinity of the retinal Schiff base and small re-arrangement of the hydrogen-bonding network in the proton release channel. On the other hand, aromatic residues surrounding the retinal polyene chain were found to scarcely move during the dark/light adaptation. This result suggests that variation in the structural rigidity within the retinal-binding pocket is one of the important factors ensuring the stereospecific isomerization of retinal.
About this Structure
1X0S is a Single protein structure of sequence from Halobacterium salinarum. Full crystallographic information is available from OCA.
Reference
Crystal structure of the 13-cis isomer of bacteriorhodopsin in the dark-adapted state., Nishikawa T, Murakami M, Kouyama T, J Mol Biol. 2005 Sep 16;352(2):319-28. PMID:16084526 Page seeded by OCA on Sat May 3 14:23:18 2008
