Related Experiment Video
Updated: May 25, 2026

Isolation and Characterization of Intact Phycobilisome in Cyanobacteria
Published on: November 10, 2021
CryB from Rhodobacter sphaeroides: a unique class of cryptochromes with new cofactors
Yann Geisselbrecht1, Sebastian Frühwirth, Claudia Schroeder
1Department of Chemistry-Institute of Biochemistry, Philipps-University, Marburg, Germany.
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.
Related Concept Videos
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Anoxygenic Phototrophic Bacteria
Diversity of Archaea III
The Photochemical Reaction Center
Bacterial Phylum Cyanobacteria
Anoxygenic Photosynthesis

