Involved in the degradation of ectoine, which allows H.elongata to utilize ectoine as both a carbon and a nitrogen source for growth. Catalyzes the hydrolysis of ectoine to N-acetyl-L-2,4-diaminobutyric acid (N-Ac-DABA). It can produce both isoforms N-gamma-acetyl-L-2,4-diaminobutyric acid (N-gamma-Ac-DABA) and N-alpha-acetyl-L-2,4-diaminobutyric acid (-Nalpha-Ac-DABA), however N-alpha-Ac-DABA is the essential substrate for the subsequent catabolic enzyme DoeB. H2O + L-ectoine = (2S)-2-acetamido-4-aminobutanoate Cells lacking this gene are unable to grow on ectoine as carbon source. The ectoine biosynthesis and ectoine degradation operate via different isoforms of N-acetyl diamonbutyric acid: N-gamma-acetyl diamonbutyric acid is the intermediate of ectoine biosynthesis and N-alpha-acetyl diamonbutyric acid is the intermediate of ectoine degradation. Belongs to the peptidase M24 family.