Hydrolyzes adenosine 5'-monophosphoramidate substrates such as AMP-morpholidate, AMP-N-alanine methyl ester, AMP-alpha-acetyl lysine methyl ester and AMP-NH2. adenosine 5'-phosphoramidate + H2O = AMP + NH4(+) Homodimer. Expression is decreased at the stationary phase (PubMed:17588813). Expression in suppressed in the presence of Pseudomonas aeruginosa lipopolysaccharide (LPS) (PubMed:23194472). Belongs to the HINT family.