THE RELATIONSHIP BETWEEN THE TRIMETHYLATION OF LYSINE-77 AND CYTOCHROME-C METABOLISM IN SACCHAROMYCES-CEREVISIAE

1. Site directed mutations were constructed in the yeast iso-1-cytochr ome c gene adjacent to the lysine 77 (methylation site) codon. 2. Thes e mutant genes were then cloned and transformed into the S. cerevisiae strain B-6642 which contains a deficiency in the iso-1-cytochrome c g ene. 3. The resulting transformants were screened for cytochrome c pro duction using gel electrophoresis. 4. Amino acid analysis of the mutat ed cytochromes c demonstrated varying levels of trimethyllysine format ion, depending on the nature of the site directed mutation. 5. The res ulting transformants were then used as tools in order to investigate t he relationship between trimethyllysine formation and various aspects of cytochrome c metabolism including protein stability and heme conjug ation.