Catalyzes the hydroxylation of the 16-position of protoviolaceinate and protodeoxyviolaceinate to form violacein and deoxyviolacein, respectively. H(+) + NADPH + O2 + protoviolaceinate = H2O + NADP(+) + violaceinate H(+) + NADH + O2 + protoviolaceinate = H2O + NAD(+) + violaceinate H(+) + NADPH + O2 + protodeoxyviolaceinate = deoxyviolaceinate + H2O + NADP(+) H(+) + NADH + O2 + protodeoxyviolaceinate = deoxyviolaceinate + H2O + NAD(+) Pigment biosynthesis; violacein biosynthesis. By N-acylhomoserine lactone (AHL). Violacein production is used as a biosensor for the detection of quorum-sensing AHL production. Violacein possesses antibacterial, antiviral, antimicrobial, antileishmanial, trypanocidal and potential antitumoral activities.