Phenotypic consequences of limiting the conformational flexibility of the H4 C-terminal tail in yeast. (A) Plasmid-borne expression of H4 mutants with limited C-terminal tail conformational flexibility leads to decreased colony formation and sensitivity to hydroxyurea (HU) in the RMY102 genetic background. Identical numbers of cells from strains SNY091 (wild-type (WT)), SNY092 (H4G94A), SNY095 (H4G94P) and SNY093 (asf1∆) were serially diluted (5 × dilutions) onto the indicated media, and photographed after 3 days. #1 and #2 indicate two independent isolates of the same strain. (B) Growth curves of the strains used in (A). (C) Cell cycle defects. Flow cytometry analysis of asynchronous cultures of the strains used above, stained with Sytox green.