Involved in the regulation of melatonin biosynthesis by catalyzing the deacetylation of N-acetylserotonin to produce serotonin (PubMed:29247559, Ref.10). N-acetylserotonin is methylated by acetylserotonin O-methyltransferase (ASMT) to produce melatonin (N-acetyl-5-methoxytryptamine) (Probable). Deacetylates melatonin to produce 5-methoxytryptamine (PubMed:29247559, Ref.10). In vitro, deacetylates N-acetyltyramine and N-acetyltryptamine to produce tyramine and tryptamine, respectively (PubMed:29247559). H2O + N-acetylserotonin = acetate + serotonin H2O + N-acetyltyramine = acetate + tyramine H2O + N-acetyltryptamine = acetate + tryptamine H2O + melatonin = 5-methoxytryptamine + acetate Binds 1 zinc ion per subunit. The activity of this enzyme is not inhibited by butyrate, a well-known histone deacetylase inhibitor. Optimum pH is 6.8-8.8. Optimum temperature is 30 degrees Celsius. Expressed in leaves (PubMed:17399684). Expressed in coleoptiles, leaves, flag leaves and flowers (PubMed:19505461). Expressed at low levels in roots (PubMed:19505461). Down-regulated by treatment with cadmium. Belongs to the histone deacetylase family.