The ability to reversibly control protein structure and function with light would offer high spatiotemporal resolution to investigate biological processes. To enable photoresponsiveness to general proteins, we genetically incorporated into proteins a set of photoswitchable click amino acids (PSCaas), which contain both a reversible photoswitch and an additional click functional group for further modifications. Orthogonal tRNA-synthetases were evolved to genetically encode PSCaas bearing azobenzene and alkene, keto or benzylchloride in E. coli and in mammalian cells. The benzylchloride PSCaa, after incorporated into calmodulin, spontaneously generated a covalent protein bridge by reacting with a nearby cysteine via proximity-enabled bioreactivity. The resultant azobenzene bridge isomerized in response to light changing calmodulin conformation. These genetically encodable PSCaas will prove valuable to engineer photoswitchable bridges into proteins for reversible optogenetic regulation.