Function
Catalyzes the circularization of gamma-N-acetyl-alpha,gamma-diaminobutyric acid (ADABA) to ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid), which is an excellent osmoprotectant. Does not act on N-acetylated amino acids like N-alpha-acetyl-L-asparagine,N-alpha-acetyl-L-ornithine, N-alpha-acetyl-L-lysine and N-epsilon-acetyl-L-lysine.