[45] Purification of tyrosine: tRNA ligase, valine : tRNA ligase, alanine : tRNA ligase, and isoleucine : tRNA ligase from Saccharomyces cerevisiae αS288C

Publisher Summary Saccharomyces cerevisiae αS288C is a strain of baker's yeast that is widely used for genetic studies. This well-characterized organism is suitable for the preparation of both tRNA and amino acid:tRNA ligases. This organism has been strongly recommended, or an isogenic strain, for all biochemical studies involving yeast tRNA and its related enzymes. This chapter describe the preparation of homogeneous amino acid:tRNA ligases specific for tyrosine, alanine, ratine, and isoleucine from Saccharomyces cerevisiae αS288C. These ligases are the first to be reported from this organism. It is believed that the procedures described will prove generally applicable for most, if not all, of the amino acid:tRNA ligases from this organism. The chapter discusses the properties of these enzymes. The molecular weight and subunit structure of the amino acid:tRNA ligases are determined under denaturing conditions by discontinuous polyacrylamide gel electrophoresis in the presence of 1% sodium dodecyl sulfate.