Symmetries of the boundary of AdS(5)xS(5) and harmonic superspace

We study the boundary limit of the bulk isometries of AdS x S. The supercon formal symmetry is realized on the coordinates of the AdS boundary, the fer mionic superspace coordinates, and the harmonics on the sphere. We show how these may be related to the coordinates of an off-shell harmonic superspac e of SCFT living on the boundary. In the special case of d = 4, N = 2 super Yang-Mills theory, a truncation of the N = 4 SYM dual to type-IIB string t heory compactified on AdS(5) x S-5, we identify the bosonic space SU(2) / U (1) of the N = 2 harmonic superspace (known before as auxiliary) with the S -2 submanifold of the S-5.