YcgF
Protein DomainYcgF (Blrp) is an Escherichia coli full-length blue-light sensing protein that contains an N-terminal FAD-binding BLUF domain and a C-terminal EAL domain. It functions as a BLUF-family photoreceptor in which the FAD chromophore undergoes light-responsive changes, and spectroscopy indicates coupling between the BLUF photochemistry and structural responses in the full-length protein.