The enzyme, isolated from the bacterium Acidovorax citrulli, performs the deamination of melamine 15-fold faster than the deamination of ammeline. It also has activity with 2-chloro-4,6-diamino-s-triazine, but has no activity toward halo-substituted triazine ring compounds such as atrazine (cf. EC 3.8.1.8, atrazine chlorohydrolase).