The cryptochrome and photolyase families consist of structurally related flavin adenine dinucleotide (FAD) proteins that use the absorption of blue light to accomplish different tasks. The photolyasess use the blue light for light-driven electron transfer to repair UV-damaged DNA, while the cryptochromes are blue-light photoreceptors involved in the circadian clock for plants and animals [, ].Members of this subfamily are from plants; they appear mostly to be regulatory proteins that respond to blue light. For instance, Arabidopsis cryptochromes Cry1 and Cry2 antagonistically regulate primary root elongation [, ]. Cry2 is also reported to interact with CIB1 and regulate transcription and floral initiation [].
