The LOV2 Domain of Phototropin: A Reversible Photochromic Switch

摘要

Light, oxygen, or voltage (LOV) domains constitute a new class of chromoprotein modules. They form the blue-light-sensitive loci of the phototropins, a recently discovered class of plant photoreceptors that regulate a variety of responses. LOV domains consist of approximately 100 amino acids and noncovalently bind a single flavin. Blue-light absorption initiates a photochemical reaction which results in the formation of a covalent adduct between a conserved cysteine and the flavin. It is believed that this species, referred to as S390 given its absorption band in the near UV, corresponds to the signaling state of the protein.