Magerl, Kathrin and Stambolic, Ivan and Dick, Bernhard (2017) Switching from adduct formation to electron transfer in a light-oxygen-voltage domain containing the reactive cysteine. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 19 (17). pp. 10808-10819. ISSN 1463-9076, 1463-9084
Full text not available from this repository. (Request a copy)Abstract
LOV (light-, oxygen- or voltage-sensitive) domains act as photosensory units of many prokaryotic and eukaryotic proteins. Upon blue light excitation they undergo a photocycle via the excited triplet state of their flavin chromophore yielding the flavin-cysteinyl adduct. Adduct formation is highly conserved among all LOV domains and constitutes the primary step of LOV domain signaling. But recently, it has been shown that signal propagation can also be triggered by flavin photoreduction to the neutral semiquinone offering new prospects for protein engineering. This, however, requires mutation of the photo-active Cys. Here, we report on LOV1 mutants of C. reinhardtii phototropin in which adduct formation is suppressed although the photo-active Cys is present. Introduction of a Tyr into the LOV core induces a proton coupled electron transfer towards the flavin chromophore. Flavin radical species are formed via either the excited flavin singlet or triplet state depending on the geometry of donor and acceptor. This photoreductive pathway resembles the photoreaction observed in other blue light photoreceptors, e.g. blue-light sensors using flavin adenine dinucleotide (BLUF) domains or cryptochromes. The ability to tune the photoreactivity of the flavin chromophore inside the LOV core has implications for the mechanism of adduct formation in the wild type and may be of use for protein engineering.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | CHLAMYDOMONAS-REINHARDTII; FLAVIN MONONUCLEOTIDE; LOV DOMAINS; SIGNAL-TRANSDUCTION; PLANT CRYPTOCHROME; BLUF DOMAIN; PHOTORECEPTOR PHOTOTROPIN; PHOT-LOV1 DOMAIN; REDOX PROPERTIES; RADICAL PAIR; |
| Subjects: | 500 Science > 530 Physics 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Bernhard Dick |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 Dec 2018 13:10 |
| Last Modified: | 26 Feb 2019 08:20 |
| URI: | https://pred.uni-regensburg.de/id/eprint/891 |
Actions (login required)
 |
View Item |
