One of an enzyme pair that work together to convert the A antigen to the H antigen of the O blood type, which together release galactosamine. Catalyzes the first step in the conversion, generating the substrate for the subsequent enzyme (FpGalNase, AC P0DTR5). Works on many different A antigen subtypes. Glu-90 probably activates a nucleophilic water molecule to start the deacetylation reaction. an N-acetyl-alpha-D-galactosaminyl-(1->3)-[alpha-L-fucosyl-(1->2)]-beta-D-galactosyl derivative + H2O = acetate + an alpha-D-galactosaminyl-(1->3)-[alpha-L-fucosyl-(1->2)]-beta-D-galactosyl derivative Inhibited by EDTA. Optimum pH is 8.0. The deacetylase domain is in the N-terminus, while the C-terminus has a CBM32-type carbohydrate-binding domain that is not required for activity on soluble substrates. The CBM32 domain binds preferentially to repeating N-acetyl lactosamine structures. 5 ug/ml of this enzyme pair converts A blood type to O blood type in an hour, and can be removed by centrifugation, showing the pair can be used for production of universal type donor blood. DNA was isolated from a male human fecal sample of AB+ blood type, the sequence was given to UniProtKB by the submitters. Dropping barriers - Issue 220 of December 2019