4D9S

Crystal structure of Arabidopsis thaliana UVR8 (UV Resistance locus 8)

Summary for 4D9S

• Entry DOI: 10.2210/pdb4d9s/pdb
• Descriptor: UVB-resistance protein UVR8 (2 entities in total)
• Functional Keywords: uv resistance, uv-b photoreceptor, tryptophan chromophores, homodimer, cop1, chromatin-binding protein
• Biological source: Arabidopsis thaliana (mouse-ear cress,thale-cress)
• Total number of polymer chains: 2
• Total formula weight: 87102.48

Authors

Arvai, A.S.,Christie, J.M.,Pratt, A.J.,Hitomi, K.,Getzoff, E.D. (deposition date: 2012-01-11, release date: 2012-04-04, Last modification date: 2023-09-13)

Primary citation

Christie, J.M.,Arvai, A.S.,Baxter, K.J.,Heilmann, M.,Pratt, A.J.,O'Hara, A.,Kelly, S.M.,Hothorn, M.,Smith, B.O.,Hitomi, K.,Jenkins, G.I.,Getzoff, E.D.
Plant UVR8 Photoreceptor Senses UV-B by Tryptophan-Mediated Disruption of Cross-Dimer Salt Bridges.
Science, 335:1492-1496, 2012

PubMed Abstract: The recently identified plant photoreceptor UVR8 (UV RESISTANCE LOCUS 8) triggers regulatory changes in gene expression in response to ultraviolet-B (UV-B) light through an unknown mechanism. Here, crystallographic and solution structures of the UVR8 homodimer, together with mutagenesis and far-UV circular dichroism spectroscopy, reveal its mechanisms for UV-B perception and signal transduction. β-propeller subunits form a remarkable, tryptophan-dominated, dimer interface stitched together by a complex salt-bridge network. Salt-bridging arginines flank the excitonically coupled cross-dimer tryptophan "pyramid" responsible for UV-B sensing. Photoreception reversibly disrupts salt bridges, triggering dimer dissociation and signal initiation. Mutation of a single tryptophan to phenylalanine retunes the photoreceptor to detect UV-C wavelengths. Our analyses establish how UVR8 functions as a photoreceptor without a prosthetic chromophore to promote plant development and survival in sunlight.

PubMed: 22323738
DOI: 10.1126/science.1218091

Experimental method

X-RAY DIFFRACTION (1.701 Å)