This domain is found in yeast PIH1 and its homologues. This domain consists of a seven-stranded beta sandwich with the topology of a CS domain, a structural motif also found in Hsp90 co-chaperones such as p23/Sba1 and Sgt1 [1].

1: Structural basis for phosphorylation-dependent recruitment of Tel2 to Hsp90 by Pih1. Pal M, Morgan M, Phelps SE, Roe SM, Parry-Morris S, Downs JA, Polier S, Pearl LH, Prodromou C; Structure. 2014;22:805-818. PMID:24794838