Antibodies that include a sulfatase motif-containing tag in a constant region of an immunoglobulin (Ig) light chain polypeptide are disclosed. The sulfatase motif can be converted by a formylglycine-generating enzyme (FGE) to produce a formylglycine (fGly)-modified Ig light chain polypeptide. An fGly-modified Ig light chain polypeptide of the antibody can be covalently and site-specifically bound to a moiety of interest to provide an antibody conjugate. The disclosure also encompasses methods of production of such tagged Ig light chain polypeptides, fGly-modified Ig light chain polypeptides, and antibody conjugates, as well as methods of use of same.
