Fig. 5. Deletion analysis of Sas2p, Sas4p and Sas5p and their cellular localizations. (A) Predicted domains, motifs and nuclear localization signals (NLS) of Sas2p, Sas4p and Sas5p. The indicated domains/motifs were found by sequence analysis with the Prosite motif scan and the SMART domain search program. NLSs are depicted as green triangles; an asterisk indicates that the NLS could not be verified experimentally. In Sas2p, the histone acetyltransferase (HAT) domain is shown (red), preceded by a zinc finger motif (yellow). A cullin homology domain (orange) was found in Sas4p. Sas5p has sequence homology to the YEATS family of proteins (blue hexagon). (B) The N-terminal domains of Sas2p and Sas5p were necessary for their nuclear accumulation. Full-length or fragments of Sas2p, Sas4p and Sas5p (pAE1098-pAE1108, Table 2) were expressed as fusions to GFP in wild-type yeast cells and visualized by fluorescence microscopy. The start and end point of each fusion is indicated by their corresponding amino acids to the left of each image. Bar, 5 µm.