Structure and function of bovine rhodopsin
Tetsuji Okada
Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064,Japan.

Photoreceptor proteins of rods and cones in the retina, rhodopsin andcolor pigments, are the members of heptahelical G protein-coupled
receptors (GPCRs). They have a covalently bound inverse agonist,
11-cis form of retinal (Vitamin A aldehyde), as the chromophore forcapturing photons. The initial process of vision is triggered by cis-transphotoisomerization of the retinal protonated Schiff base attached to alysine side chain in transmembrane helix VII. This reaction can beconsidered as an instantaneous conversion from an inverse-agonist to anagonist, which subsequently evokes the activation of the protein.
The first crystal structure of rhodopsin was determined at 2.8 Å
resolutions in 2000.1 Since then, several new coordinates have beenobtained, including the ground state at higher resolution (blue ribbon in
the figure),2,3 two photoreaction intermediates 4,5 and a 9-cis-analogue
pigment.6 In addition, some other crystal structures have been reported in different space groups.7-9These recent advances are summarized in the context of visual function, and the discussion will also
include some comparison with the new structure of the human β2-adrenergic receptor (red ribbon).10
X-ray crystallographic and quantum chemical studies of bovine rhodopsin in P41 space group
have been contributed by the following researchers: (alphabetical order) CA Behnke, AN Bondar, VBuss, M Elstner, P Entel, BA Fox, Y Fujiyoshi, T Hori, T Kumasaka, EM Landau, I Le Trong, MMiyano, H Motoshima, H Nakamichi, J Navarro, K Palczewski, M Schreiber, S Sekharan, YShichida, M Silow, RE Stenkamp, M Sugihara, DC Teller, M Yamamoto, O Weingart. Support at thebeamlines of SPring-8 is gratefully acknowledged.
[1] Palczewski, K., Kumasaka, T., Hori, T., Behnke, C.A., Motoshima, H., Fox, B.A., Le Trong, I., Teller, D.C., Okada, T.,
Stenkamp, R.E., Yamamoto, M., and Miyano, M. (2000) Science 289, 739-745..
[2] Okada, T., Fujiyoshi, Y., Silow, M., Navarro, J., Landau, E. M. & Shichida, Y. (2002) Proc. Natl. Acad. Sci. USA. 99,5982-5987.
[3] Okada, T., Sugihara, M., Bondar, A. N., Elstner,, M., Entel, P., and Buss, V., (2004) J. Mol. Biol., 342, 571-581.
[4] Nakamichi, H., and Okada, T., (2006) Angew Chem Int Ed 45, 4270-4273[5] Nakamichi, H., and Okada, T., (2006) Proc Natl Acad Sci USA 103, 12729-12734[6] Sekharan, S., Sugihara, M., Weingart, O., Okada, T., and Buss, V., (2007) J Am Chem Soc 129, 1052-1054[7] Li, J., Edwards, P. C., Burghammer, M., Villa, C., and Schertler, G. F., (2004) J. Mol. Biol. 343, 1409-1438.
[8] Standfuss, J., Xie, G., Edwards, P. C., Burghammer, M., Oprian, D. D., Schertler, G. F., (2007) J. Mol. Biol., 372,1179-1188.
[9] Salom, D., Lodowski, D.T., Stenkamp, R.E., Le Trong, I., Golczak, M., Jastrzebska, B., Harris,T., Ballesteros, J.A.,
and Palczewski , K. (2006) Proc. Natl. Acad. Sci. USA 103, 16123-16128.
[10] Cherezov, V., Rosenbaum, D. M., Hanson, M. A., Rasmussen, S. G., Thian, F. S., Kobilka, T. S., Choi, H. J., Kuhn, P.,Weis, W. I., Kobilka, B. K., snd Stevens, R..C., (2007) Science 318, 1258-1265.