LOV2-linker-kinase phosphorylates LOV1-containing N-terminal polypeptide substrate via photoreaction of LOV2 in Arabidopsis phototropin1

► LOV2-linker kinase of Arabidopsis phot1 was prepared. ► The kinase showed a similar photoreaction with LOV2-core. ► The kinase phosphorylated a substrate consisting of the N-terminal part of phot1. ► Amino acid substitution showed activation of the kinase via photoreaction of LOV2.