Fedorov, Roman and Schlichting, Ilme and Hartmann, Elisabeth and Domratcheva, Tatjana and Fuhrmann, Markus and Hegemann, Peter (2003) Crystal structures and molecular mechanism of a light-induced signaling switch: The Phot-LOV1 domain from Chlamydomonas reinhardtii. BIOPHYSICAL JOURNAL, 84 (4). pp. 2474-2482. ISSN 0006-3495
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Phot proteins (phototropins and homologs) are blue-light photoreceptors that control mechanical processes like phototropism, chloroplast relocation, or guard-cell opening in plants. Phot receptors consist of two flavin mononucleotide (FMN)-binding light, oxygen, or voltage (LOV) domains and a C-terminal serine/threonine kinase domain. We determined crystal structures of the LOV1 domain of Phot1 from the green alga Chlamydomonas reinhardtii in the dark and illuminated state to 1.9 Angstrom and 2.8 Angstrom resolution, respectively. The structure resembles that of LOV2 from Adiantum (Crosson, S. and K. Moffat. 2001. Proc. Natl. Acad. Sci. USA. 98:2995-3000). In the resting dark state of LOV1, the reactive Cys-57 is present in two conformations. Blue-light absorption causes formation of a proposed active signaling state that is characterized by a covalent bond between the flavin C4a and the thiol of Cys-57. There are differences around the FMN chromophore but no large overall conformational changes. Quantum chemical calculations based on the crystal structures revealed the electronic distribution in the active site during the photocycle. The results suggest trajectories for electrons, protons, and the active site cysteine and offer an interpretation of the reaction mechanism.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | MERCURIC ION REDUCTASE; BLUE-LIGHT; PHOTORECEPTOR PHOTOTROPIN; FLAVIN MONONUCLEOTIDE; CATALYTIC PATHWAY; ARABIDOPSIS NPH1; OXYGEN; REDOX; RESOLUTION; SENSORS; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie I |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 15 Sep 2021 06:23 |
| Last Modified: | 15 Sep 2021 06:23 |
| URI: | https://pred.uni-regensburg.de/id/eprint/39136 |
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