Dataset Information

Extended Electron-Transfer in Animal Cryptochromes Mediated by a Tetrad of Aromatic Amino Acids.

ABSTRACT: The cryptochrome/photolyase protein family possesses a conserved triad of tryptophans that may act as a molecular wire to transport electrons from the protein surface to the FAD cofactor for activation and/or signaling-state formation. Members from the animal (and animal-like) cryptochrome subclade use this process in a light-induced fashion in a number of exciting responses, such as the (re-)setting of circadian rhythms or magnetoreception; however, electron-transfer pathways have not been explored in detail yet. Therefore, we present an in-depth time-resolved optical and electron-paramagnetic resonance spectroscopic study of two cryptochromes from Chlamydomonas reinhardtii and Drosophila melanogaster. The results do not only reveal the existence of a fourth, more distant aromatic amino acid that serves as a terminal electron donor in both proteins, but also show that a tyrosine is able to fulfill this very role in Chlamydomonas reinhardtii cryptochrome. Additionally, exchange of the respective fourth aromatic amino acid to redox-inactive phenylalanines still leads to light-induced radical pair formation; however, the lifetimes of these species are drastically reduced from the ms- to the ?s-range. The results presented in this study open up a new chapter, to our knowledge, in the diversity of electron-transfer pathways in cryptochromes. Moreover, they could explain unique functions of animal cryptochromes, in particular their potential roles in magnetoreception because magnetic-field effects of light-induced radical pairs strongly depend on distance and orientation parameters.

SUBMITTER: Nohr D

PROVIDER: S-EPMC4968396 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

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Extended Electron-Transfer in Animal Cryptochromes Mediated by a Tetrad of Aromatic Amino Acids.

Nohr Daniel D Franz Sophie S Rodriguez Ryan R Paulus Bernd B Essen Lars-Oliver LO Weber Stefan S Schleicher Erik E

Biophysical journal 20160701 2

The cryptochrome/photolyase protein family possesses a conserved triad of tryptophans that may act as a molecular wire to transport electrons from the protein surface to the FAD cofactor for activation and/or signaling-state formation. Members from the animal (and animal-like) cryptochrome subclade use this process in a light-induced fashion in a number of exciting responses, such as the (re-)setting of circadian rhythms or magnetoreception; however, electron-transfer pathways have not been expl ...[more]

PMID: 27463133

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Dataset Information

Extended Electron-Transfer in Animal Cryptochromes Mediated by a Tetrad of Aromatic Amino Acids.

Publications

Extended Electron-Transfer in Animal Cryptochromes Mediated by a Tetrad of Aromatic Amino Acids.

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