title: Identification of a new cryptochrome class. Structure, function, and evolution.
abstract: Cryptochrome flavoproteins, which share sequence homology with light-dependent DNA repair photolyases, function as photoreceptors in plants and circadian clock components in animals. Here, we coupled sequencing of an Arabidopsis cryptochrome gene with phylogenetic, structural, and functional analyses to identify a new cryptochrome class (cryptochrome DASH) in bacteria and plants, suggesting that cryptochromes evolved before the divergence of eukaryotes and prokaryotes. The cryptochrome crystallographic structure, reported here for Synechocystis cryptochrome DASH, reveals commonalities with photolyases in DNA binding and redox-dependent function, despite distinct active-site and interaction surface features. Whole genome transcriptional profiling together with experimental confirmation of DNA binding indicated that Synechocystis cryptochrome DASH functions as a transcriptional repressor.
authors.affiliation: Department of Molecular Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Brudler
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hitomi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Daiyasu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Toh
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kucho
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ishiura
authors.forename: Minoru
authors.initials: M
authors.lastname: Kanehisa
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Roberts
authors.forename: Takeshi
authors.initials: T
authors.lastname: Todo
authors.forename: John A
authors.initials: JA
authors.lastname: Tainer
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Getzoff
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D001683:Biological Clocks; D056931:Cryptochromes; D018360:Crystallography, X-Ray; D000458:Cyanobacteria / Q000737:chemistry / Q000378:metabolism; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D005136:Eye Proteins; D005420:Flavoproteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D017956:Photoreceptor Cells, Invertebrate; D010802:Phylogeny; D043562:Receptors, G-Protein-Coupled; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; C538962:CRY1 protein, Arabidopsis; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; D004255:Deoxyribodipyrimidine Photo-Lyase