title: CryB from Rhodobacter sphaeroides: a unique class of cryptochromes with new cofactors.
abstract: Cryptochromes and photolyases are structurally related but have different biological functions in signalling and DNA repair. Proteobacteria and cyanobacteria harbour a new class of cryptochromes, called CryPro. We have solved the 2.7 Å structure of one of its members, cryptochrome B from Rhodobacter sphaeroides, which is a regulator of photosynthesis gene expression. The structure reveals that, in addition to the photolyase-like fold, CryB contains two cofactors only conserved in the CryPro subfamily: 6,7-dimethyl-8-ribityl-lumazine in the antenna-binding domain and a [4Fe-4S] cluster within the catalytic domain. The latter closely resembles the iron-sulphur cluster harbouring the large primase subunit PriL, indicating that PriL is evolutionarily related to the CryPro class of cryptochromes.
authors.affiliation: Department of Chemistry-Institute of Biochemistry, Philipps-University, Marburg, Germany.
authors.forename: Yann
authors.initials: Y
authors.lastname: Geisselbrecht
authors.forename: Sebastian
authors.initials: S
authors.lastname: Frühwirth
authors.forename: Claudia
authors.initials: C
authors.lastname: Schroeder
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Pierik
authors.forename: Gabriele
authors.initials: G
authors.lastname: Klug
authors.forename: Lars-Oliver
authors.initials: LO
authors.lastname: Essen
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D001665:Binding Sites; D056931:Cryptochromes / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D018360:Crystallography, X-Ray; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry / Q000235:genetics; D005295:Ferrocyanides / Q000737:chemistry; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011621:Pteridines / Q000737:chemistry; D012242:Rhodobacter sphaeroides / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D056931:Cryptochromes; D005295:Ferrocyanides; D011621:Pteridines; D005182:Flavin-Adenine Dinucleotide; C001061:6,7-dimethyl-8-ribityllumazine; D004255:Deoxyribodipyrimidine Photo-Lyase