This family consists of immunoglobulin A1 protease proteins. The immunoglobulin A1 protease cleaves immunoglobulin IgA and is found in pathogenic bacteria such as Neisseria gonorrhoeae. Not all of the members of this family are IgA proteases Swiss:O32555 from E. coli O157:H7 cleaves human coagulation factor V and Swiss:O88093 is a hemoglobin protease from E. coli EB1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",