Methyl-Deficient Transfer Ribonucleic Acid and Macromolecular Synthesis in Methionine-Starved Saccharomyces cerevisiae

AUTOR(ES)

Kjellin-Stråby, Kerstin

RESUMO

Haploid methionine auxotrophs of Saccharomyces cerevisiae continue to multiply for several hours after withdrawal of a required amino acid from the medium. Macro-molecular synthesis continues during this period of residual growth, although the net ribonucleic acid (RNA) and protein content is constant during the later part of this period. In this study, growth after withdrawal of methionine was in some cases accompanied by accumulation of transfer RNA (tRNA), which was shown by methylation in vitro to be deficient in methyl groups. This phenomenon was shown by only four of nine methionine auxotrophs tested, but no evidence could be found that these four strains had “relaxed” control of RNA synthesis. The nine methionine-requiring strains represent mutations in five different positions in the methionine biosynthesis pathway, and only mutants blocked at two of these five positions accumulated methyl-deficient tRNA. This accumulation therefore appears to be correlated with the position of the strain's block in the pathway of methionine biosynthesis.

Documentos Relacionados

• Methyl-Deficient Transfer Ribonucleic Acid in Saccharomyces cerevisiae
• Influence of Methionine Pool Composition on the Formation of Methyl-Deficient Transfer Ribonucleic Acid in Saccharomyces cerevisiae
• Studies on Microbial Ribonucleic Acid VI. Appearance of Methyl-deficient Transfer Ribonucleic Acid During Logarithmic Growth of Saccharomyces cerevisiae
• Relationship Between Methionyl Transfer Ribonucleic Acid Cellular Content and Synthesis of Methionine Enzymes in Saccharomyces cerevisiae
• Detection of nucleoside Q precursor in methyl-deficient E.coli tRNA.