Changes in translational accuracy of Escherichia coli when folate metabolism is perturbed.
Translational accuracy was monitored in Escherichia coli mutants which contain abnormal folate pools. A decrease in translational accuracy was indicated by the increased production of a T4 phage mutant containing a UGA mutation in a tail fibre gene. An E. coli folC mutant suppressed the phage mutant under conditions where it presumably accumulated methyl-tetrahydrofolate (methyl-THF). A UGA suppressor strain with the mutation affecting the primary structure of the tRNA(trp) normally suppressed the phage mutant. When the strain was made thymine-requiring it no longer suppressed. The accumulation of methyl-THF which permits suppression by thymine-requiring strains may act to interfere with suppression by the tRNA suppressor, possibly by changing the modification pattern of the tRNA.
Basso
J
J
Department of Chemistry and Biochemistry, Concordia University, Montreal, Quebec, Canada.
Herrington
M B
MB
D000630:Aminopterin / Q000494:pharmacology; D003090:Coliphages / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005492:Folic Acid / Q000378:metabolism*; D005493:Folic Acid Antagonists; D005798:Genes, Bacterial / Q000235:genetics; D008715:Methionine / Q000378:metabolism; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis / Q000502:physiology*; D012364:RNA, Transfer, Trp / Q000235:genetics; D013489:Suppression, Genetic / Q000235:genetics*; D013763:Tetrahydrofolates / Q000378:metabolism; D013940:Thymidylate Synthase / Q000235:genetics
D005493:Folic Acid Antagonists; D012364:RNA, Transfer, Trp; D013763:Tetrahydrofolates; D005492:Folic Acid; D008715:Methionine; D013940:Thymidylate Synthase; D010453:Peptide Synthases; C020041:dihydrofolate synthetase; C023103:folylpolyglutamate synthetase; D000630:Aminopterin