1. On the midpoint potential of the FAD chromophore in a BLUF-domain containing photoreceptor protein.
- Author
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Arents JC, Perez MA, Hendriks J, and Hellingwerf KJ
- Subjects
- Algorithms, Amino Acid Sequence, Bacterial Proteins chemistry, Bacterial Proteins genetics, Binding Sites genetics, Cryptochromes chemistry, Cryptochromes metabolism, Flavin-Adenine Dinucleotide chemistry, Flavins chemistry, Flavins metabolism, Flavoproteins chemistry, Flavoproteins genetics, Kinetics, Light, Mutagenesis, Site-Directed, Oxidation-Reduction drug effects, Oxidation-Reduction radiation effects, Oxygen pharmacology, Photoreceptors, Microbial chemistry, Photoreceptors, Microbial metabolism, Rhodobacter sphaeroides genetics, Spectrophotometry, Bacterial Proteins metabolism, Flavin-Adenine Dinucleotide metabolism, Flavoproteins metabolism, Rhodobacter sphaeroides metabolism
- Abstract
The redox-midpoint potential of the FAD chromophore in the BLUF domain of anti-transcriptional regulator AppA from Rhodobacter sphaeroides equals ∼-260mV relative to the calomel electrode. Altering the structure of its chromophore-binding pocket through site-directed mutagenesis brings this midpoint potential closer to that of free flavin in aqueous solution. The redox-midpoint potential of this BLUF domain is intermediate between those of LOV domains and Cryptochromes, which may rationalize the primary photochemistry observed in these three flavin-containing photoreceptor families. These results also imply that LOV domains, among the flavin-containing photosensory receptors, are least sensitive to intracellular chemical reduction in the dark., (Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)
- Published
- 2011
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