Using the SPring-8 synchrotron facility which allows the rapid determination of minute structural changes by small-angle x-ray scattering, the researchers elucidated the mechanism of this complex kinase. The 1000 amino acid protein complex phototropin consists of two domains LOV1 and LOV2 of which each contains an FAD residue. If LOV2 receives blue light, the signal is transmitted to the phosphorylated enzyme domain, leading to an induction of phosphorylation of other proteins.

RIKEN news release, September 17, 2016