2PYR

PHOTOACTIVE YELLOW PROTEIN, 1 NANOSECOND INTERMEDIATE (287K)

Summary for 2PYR

• Entry DOI: 10.2210/pdb2pyr/pdb
• Descriptor: PHOTOACTIVE YELLOW PROTEIN, 4'-HYDROXYCINNAMIC ACID (3 entities in total)
• Functional Keywords: photoreceptor, light sensor for negative phototaxis
• Biological source: Halorhodospira halophila
• Total number of polymer chains: 1
• Total formula weight: 14052.73

Authors

Perman, B.,Srajer, V.,Ren, Z.,Teng, T.Y.,Pradervand, C.,Ursby, T.,Bourgeois, D.,Schotte, F.,Wulff, M.,Kort, R.,Hellingwerf, K.,Moffat, K. (deposition date: 1998-03-04, release date: 1999-04-06, Last modification date: 2011-07-13)

Primary citation

Perman, B.,Srajer, V.,Ren, Z.,Teng, T.,Pradervand, C.,Ursby, T.,Bourgeois, D.,Schotte, F.,Wulff, M.,Kort, R.,Hellingwerf, K.,Moffat, K.
Energy transduction on the nanosecond time scale: early structural events in a xanthopsin photocycle.
Science, 279:1946-1950, 1998

PubMed Abstract: Photoactive yellow protein (PYP) is a member of the xanthopsin family of eubacterial blue-light photoreceptors. On absorption of light, PYP enters a photocycle that ultimately transduces the energy contained in a light signal into an altered biological response. Nanosecond time-resolved x-ray crystallography was used to determine the structure of the short-lived, red-shifted, intermediate state denoted [pR], which develops within 1 nanosecond after photoelectronic excitation of the chromophore of PYP by absorption of light. The resulting structural model demonstrates that the [pR] state possesses the cis conformation of the 4-hydroxyl cinnamic thioester chromophore, and that the process of trans to cis isomerization is accompanied by the specific formation of new hydrogen bonds that replace those broken upon excitation of the chromophore. Regions of flexibility that compose the chromophore-binding pocket serve to lower the activation energy barrier between the dark state, denoted pG, and [pR], and help initiate entrance into the photocycle. Direct structural evidence is provided for the initial processes of transduction of light energy, which ultimately translate into a physiological signal.

PubMed: 9506946
DOI: 10.1126/science.279.5358.1946

Experimental method

X-RAY DIFFRACTION (1.9 Å)