Tag:AsLOV2 corresponds to the flavin binding domain (LOV2) and carboxy-terminal helical extension (Jα) of the Avena sativa Phototropin 1 (PT1) gene. Tag:AsLOV2 can be fused to another protein to produce a photactivatable form of that protein. This is because the photoreactive LOV domain interacts with the Jα domain in the dark, while photon absorption leads to conformational changes that result in dissociation and unwinding of the Jα helix. Thus in the dark in its closed conformation, the Tag:AsLOV2 sequence can sterically block activation of the protein it is fused to, while the light-induced conformational changes can release this steric inhibition (PMID:19693014, reviewed in PMID:25988185).
