5TE5

Crystal structure of Bos taurus opsin regenerated with 6-carbon ring retinal chromophore

Summary for 5TE5

• Entry DOI: 10.2210/pdb5te5/pdb
• Related: 5TE3
• Descriptor: Rhodopsin, (2E)-{(4E)-4-[(3E)-4-(2,6,6-trimethylcyclohex-1-en-1-yl)but-3-en-2-ylidene]cyclohex-2-en-1-ylidene}acetaldehyde (2 entities in total)
• Functional Keywords: signaling protein
• Biological source: Bos taurus (Bovine)
• Cellular location: Membrane; Multi-pass membrane protein: P02699
• Total number of polymer chains: 1
• Total formula weight: 39353.94

Authors

Gulati, S.,Banerjee, S.,Katayama, K.,Kiser, P.D.,Palczewski, K. (deposition date: 2016-09-20, release date: 2017-03-15, Last modification date: 2024-11-20)

Primary citation

Gulati, S.,Jastrzebska, B.,Banerjee, S.,Placeres, A.L.,Miszta, P.,Gao, S.,Gunderson, K.,Tochtrop, G.P.,Filipek, S.,Katayama, K.,Kiser, P.D.,Mogi, M.,Stewart, P.L.,Palczewski, K.
Photocyclic behavior of rhodopsin induced by an atypical isomerization mechanism.
Proc. Natl. Acad. Sci. U.S.A., 114:E2608-E2615, 2017

PubMed Abstract: Vertebrate rhodopsin (Rh) contains 11--retinal as a chromophore to convert light energy into visual signals. On absorption of light, 11--retinal is isomerized to all--retinal, constituting a one-way reaction that activates transducin (G) followed by chromophore release. Here we report that bovine Rh, regenerated instead with a six-carbon-ring retinal chromophore featuring a C=C double bond locked in its conformation (Rh6mr), employs an atypical isomerization mechanism by converting 11- to an 11,13- configuration for prolonged G activation. Time-dependent UV-vis spectroscopy, HPLC, and molecular mechanics analyses revealed an atypical thermal reisomerization of the 11,13- to the 11- configuration on a slow timescale, which enables Rh6mr to function in a photocyclic manner similar to that of microbial Rhs. With this photocyclic behavior, Rh6mr repeatedly recruits and activates G in response to light stimuli, making it an excellent candidate for optogenetic tools based on retinal analog-bound vertebrate Rhs. Overall, these comprehensive structure-function studies unveil a unique photocyclic mechanism of Rh activation by an 11--to-11,13- isomerization.

PubMed: 28289214
DOI: 10.1073/pnas.1617446114

Experimental method

X-RAY DIFFRACTION (4.01 Å)