Fig. 5. Mutation sites in Pkc1p. (A) The pkc1-834 mutant allele carries a single nucleotide change (A2501G) that causes replacement of asparagine 834 with aspartic acid. The stt1-1 mutant allele carries a single nucleotide change (C3304T) that causes replacement of proline 1102 with serine. (B) The amino acids P1102 and N834 of Pkc1p are important for its function. pkc1 or zds1 pkc1 cells with low-copy plasmids, carrying either PKC1 (YCp50-PKC1), stt1-1 (YCp50-PKC1P1102S) or pkc1-834 (YCp50-PKC1N834D), were spotted on YPD plate with or without 300 mM CaCl₂ and grown at the indicated temperatures for 23 days.