title: Purification and characterization of three members of the photolyase/cryptochrome family blue-light photoreceptors from Vibrio cholerae.
abstract: The sequence of Vibrio cholerae genome revealed three genes belonging to the photolyase/cryptochrome blue-light photoreceptor family. The proteins encoded by the three genes were purified and characterized. All three proteins contain folate and flavin cofactors and have absorption peaks in the range of 350-500 nm. Only one of the three, VcPhr, is a photolyase specific for cyclobutane pyrimidine dimers. The other two are cryptochromes and were designated VcCry1 and VcCry2, respectively. Mutation of phr abolishes photoreactivation of UV-induced killing, whereas mutations in cry1 and cry2 do not affect photorepair activity. VcCry1 exhibits some unique features. Of all cryptochromes characterized to date, it is the only one that contains stoichiometric amounts of both chromophores and retains its flavin cofactor in the two-electron reduced FADH2 form. In addition, VcCry1 exhibits RNA binding activity and co-purifies with an RNA of 60-70 nucleotides in length.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA.
authors.forename: Erin N
authors.initials: EN
authors.lastname: Worthington
authors.forename: I Halil
authors.initials: IH
authors.lastname: Kavakli
authors.forename: Gloria
authors.initials: G
authors.lastname: Berrocal-Tito
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Bondo
authors.forename: Aziz
authors.initials: A
authors.lastname: Sancar
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D056931:Cryptochromes; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry* / Q000302:isolation & purification; D019281:Dimerization; D004307:Dose-Response Relationship, Radiation; D029721:Drosophila Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005136:Eye Proteins; D005182:Flavin-Adenine Dinucleotide / Q000031:analogs & derivatives* / Q000737:chemistry; D005420:Flavoproteins / Q000737:chemistry* / Q000302:isolation & purification; D006358:Hot Temperature; D008024:Ligands; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D010786:Photoreceptor Cells / Q000737:chemistry*; D017956:Photoreceptor Cells, Invertebrate; D010957:Plasmids / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D014466:Ultraviolet Rays; D014734:Vibrio cholerae / Q000378:metabolism*
chemical_list: D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D008024:Ligands; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; D005182:Flavin-Adenine Dinucleotide; C058805:1,5-dihydro-FAD; D012313:RNA; D004255:Deoxyribodipyrimidine Photo-Lyase; C478398:Phr protein, Vibrio cholerae