Figure 2.

Growth characteristics of CDC6 ATP-binding site mutants. (A) A schematic of Cdc6p showing the regions of homology to RFC and the AAA⁺ superfamily of proteins (44, 45). Below is an alignment (from top to bottom) of the human (50), Xenopus (7), S. pombe (51), and S. cerevisiae (40) Cdc6p Walker A and B motifs (underlined). The amino acid changes in Cdc6p are indicated by the arrows at lysine 114 and the aspartic and glutamic acids 223 and 224. (B) Strains YB502, YB503, YB504, and YB505 were streaked onto SC plates lacking methionine (−Met), expressing pMET3-CDC6^WT, or containing 2 mM methionine (+Met), allowing expression of only the indicated CDC6 allele, and photographed after 2 days at 30°C and 37°C.