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 deacetylation of N-alpha-acetyl-L-2,4-diaminobutyrate (N-alpha-Ac-DABA) to yield L-2,4-diaminobutyrate (DABA). (2S)-2-acetamido-4-aminobutanoate + H2O = acetate + L-2,4-diaminobutanoate Binds 1 zinc ion per subunit. Cells lacking this gene are unable to grow on ectoine as carbon and nitrogen sources and accumulate N-alpha-acetyl-L-2,4-diaminobutyrate (N-alpha-Ac-DABA). Belongs to the DoeB deacetylase family.