Fig. 3. PCNA binding motif at the C–terminus of Cdc27. Aligned sequences of the PCNA binding motifs identified in eight classes of PCNA binding protein as follows: 1, p21 and p21-like proteins; 2, Fen1 nucleases; 3, XP-G nucleases; 4, DNA ligase I; 5, large subunit of RF-C; 6, MCMT methyltransferases; 7, uracil-N-glycosylase; 8, Cdc27 plus its S.cerevisiae homologue Pol32 and the recently identified human homologue p66. Hs, human; Sp, S.pombe; Sc, S.cerevisiae; Mm, Mus musculus; Dm, Drosophila melanogaster; Xl, Xenopus laevis. See Warbrick et al. (1998) for further details.