Figure 2.

RIP60 is a polydactyl ZF protein. Two otherwise identical cDNAs with different poly(A) tails were isolated from a HeLa cell lambda phage library using a clone related to 146A as probe. (A) The open reading frame of both clones predicts a 567 amino acid protein that includes 15 ZFs (bold) and both RIP60 peptide sequences obtained by microsequencing (underlined). (B) RIP60 contains 15 C₂H₂ Kruppel-like ZFs organized in three hands termed Z1 (ZFs 1–5), Z2 (ZFs 6–8) and Z3 (ZFs 9–15). A proline-rich region (PRR) predicted to form three polyproline helices separates hands Z2 and Z3.