Publication Date:
2012-02-11
Description:
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. beta-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.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3505452/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3505452/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Christie, John M -- Arvai, Andrew S -- Baxter, Katherine J -- Heilmann, Monika -- Pratt, Ashley J -- O'Hara, Andrew -- Kelly, Sharon M -- Hothorn, Michael -- Smith, Brian O -- Hitomi, Kenichi -- Jenkins, Gareth I -- Getzoff, Elizabeth D -- GM37684/GM/NIGMS NIH HHS/ -- R01 GM037684/GM/NIGMS NIH HHS/ -- Biotechnology and Biological Sciences Research Council/United Kingdom -- New York, N.Y. -- Science. 2012 Mar 23;335(6075):1492-6. doi: 10.1126/science.1218091. Epub 2012 Feb 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22323738" target="_blank"〉PubMed〈/a〉
Keywords:
Arabidopsis/physiology
;
Arabidopsis Proteins/*chemistry/genetics/*metabolism
;
Arginine/chemistry
;
Chromosomal Proteins, Non-Histone/*chemistry/genetics/*metabolism
;
Circular Dichroism
;
Crystallography, X-Ray
;
Hydrogen Bonding
;
Hydrogen-Ion Concentration
;
Light Signal Transduction
;
Models, Molecular
;
Mutagenesis
;
Photoreceptors, Plant/*chemistry/genetics/*metabolism
;
Protein Conformation
;
Protein Multimerization
;
Recombinant Fusion Proteins/chemistry/metabolism
;
Tryptophan/chemistry
;
*Ultraviolet Rays
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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