An optomechanical transducer in the blue light receptor phototropin from Avena sativa
- 16 October 2001
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 98 (22) , 12357-12361
- https://doi.org/10.1073/pnas.221455298
Abstract
The PHOT1 (NPH1) gene from Avena sativa specifies the blue light receptor for phototropism, phototropin, which comprises two FMN-binding LOV domains and a serine/threonine protein kinase domain. Light exposure is conducive to autophosphorylation of the protein kinase domain. We have reconstituted a recombinant LOV2 domain of A. sativa phototropin with various (13)C/(15)N-labeled isotopomers of the cofactor, FMN. The reconstituted protein samples were analyzed by NMR spectroscopy under dark and light conditions. Blue light irradiation is shown to result in the addition of a thiol group (cysteine 450) to the 4a position of the FMN chromophore. The adduct reverts spontaneously in the dark by elimination. The light-driven flavin adduct formation results in conformational modification, which was diagnosed by (1)H and (31)P NMR spectroscopy. This conformational change is proposed to initiate the transmission of the light signal via conformational modulation of the protein kinase domain conducive to autophosphorylation of NPH1.Keywords
This publication has 29 references indexed in Scilit:
- The Intraflavin Hydrogen Bond in Human Electron Transfer Flavoprotein Modulates Redox Potentials and May Participate in Electron TransferBiochemistry, 1999
- Arabidopsis NPH1: A Protein Kinase with a Putative Redox-Sensing DomainScience, 1997
- PHH1, a novel gene from Arabidopsis thaliana that encodes a protein similar to plant blue-light photoreceptors and microbial photolyasesMolecular Genetics and Genomics, 1996
- Use of a site-directed triple mutant to trap intermediates: demonstration that the flavin C(4a)-thiol adduct and reduced flavin are kinetically competent intermediates in mercuric ion reductaseBiochemistry, 1990
- Flavodoxin from Anabaena 7120: uniform nitrogen-15 enrichment and hydrogen-1, nitrogen-15, and phosphorus-31 NMR investigations of the flavin mononucleotide binding site in the reduced and oxidized statesBiochemistry, 1988
- Carbon‐13 and nitrogen‐15 nuclear‐magnetic‐resonance investigation on Desulfovibrio vulgaris flavodoxinEuropean Journal of Biochemistry, 1985
- Reinvestigation of the structure of oxidized and reduced flavin: carbon-13 and nitrogen-15 nuclear magnetic resonance studyBiochemistry, 1984
- A 13C Nuclear‐Magnetic‐Resonance Study on Free Flavins and Megasphaera elsdenii and Azotobacter vinelandii FlavodoxinEuropean Journal of Biochemistry, 1981
- A Comparative 13C‐NMR. Study on Various Reduced FlavinsHelvetica Chimica Acta, 1980
- Oxidation of thiophenol and nitroalkanes by an electron deficient isoalloxazineJournal of the American Chemical Society, 1975