2OOL

Crystal structure of the chromophore-binding domain of an unusual bacteriophytochrome RpBphP3 from R. palustris

Summary for 2OOL

• Entry DOI: 10.2210/pdb2ool/pdb
• Descriptor: Sensor protein, 3-[2-[(Z)-[3-(2-carboxyethyl)-5-[(Z)-(4-ethenyl-3-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-4-methyl-pyrrol-1-ium -2-ylidene]methyl]-5-[(Z)-[(3E)-3-ethylidene-4-methyl-5-oxidanylidene-pyrrolidin-2-ylidene]methyl]-4-methyl-1H-pyrrol-3- yl]propanoic acid (3 entities in total)
• Functional Keywords: bacteriophytochrome, photoconversion, photoreceptor, biliverdin, signaling protein
• Biological source: Rhodopseudomonas palustris
• Total number of polymer chains: 2
• Total formula weight: 75834.22

Authors

Yang, X.,Stojkovic, E.A.,Kuk, J.,Moffat, K. (deposition date: 2007-01-25, release date: 2007-07-10, Last modification date: 2024-11-06)

Primary citation

Yang, X.,Stojkovic, E.A.,Kuk, J.,Moffat, K.
Crystal structure of the chromophore binding domain of an unusual bacteriophytochrome, RpBphP3, reveals residues that modulate photoconversion.
Proc.Natl.Acad.Sci.Usa, 104:12571-12576, 2007

PubMed Abstract: Bacteriophytochromes RpBphP2 and RpBphP3 from the photosynthetic bacterium Rhodopseudomonas palustris work in tandem to modulate synthesis of the light-harvesting complex LH4 in response to light. Although RpBphP2 and RpBphP3 share the same domain structure with 52% sequence identity, they demonstrate distinct photoconversion behaviors. RpBphP2 exhibits the "classical" phytochrome behavior of reversible photoconversion between red (Pr) and far-red (Pfr) light-absorbing states, whereas RpBphP3 exhibits novel photoconversion between Pr and a near-red (Pnr) light-absorbing states. We have determined the crystal structure at 2.2-A resolution of the chromophore binding domains of RpBphP3, covalently bound with chromophore biliverdin IXalpha. By combining structural and sequence analyses with site-directed mutagenesis, we identify key residues that directly modulate the photochemical properties of RpBphP3 and RpBphP2. Remarkably, we identify a region spanning residues 207-212 in RpBphP3, in which a single mutation, L207Y, causes this unusual bacteriophytochrome to revert to the classical phenotype that undergoes reversible photoconversion between the Pr and Pfr states. The reverse mutation, Y193L, in the corresponding region in RpBphP2 significantly diminishes the formation of the Pfr state. We propose that residues 207-212 and the spatially adjacent conserved residues, Asp-216 and Tyr-272, interact with the chromophore and form part of the interface between the chromophore binding domains and the PHY domain that modulates photoconversion.

PubMed: 17640891
DOI: 10.1073/pnas.0701737104

Experimental method

X-RAY DIFFRACTION (2.2 Å)