Small Ribonucleic Acids of Escherichia coli II. NONCOORDINATE ACCUMULATION DURING STRINGENT CONTROL

摘要: Abstract The accumulation of small RNAs (4 to 6 S) in Escherichia coli during amino acid starvation has been studied by 10% polyacrylamide gel electrophoresis and two-dimensional fingerprint analysis. In CP78, a stringent (rel+) strain, RNA labeled with 32PO43- pattern that is very different from nonstarved cells. However, CP79, relaxed (rel-) mutant, similar normal. During the labeling 5 S RNA, 4.5 most tRNAs reduced about 5% an unstable molecule containing dihydrouracil, electrophoretic mobility also reduced. contrast, (which stable) GTP at its 5' end are much less severely reduced, if all. Thus these molecules control noncoordinate inhibition not necessarily correlated metabolic stability. When cells strain treated antibiotic trimethoprim, undermethylated form tRNALeu1 appears as highly single species RNAs. Trimethoprim treatment reduces both level bulk tRNA extent methylation. These effects trimethoprim inhibited addition methionine medium. various kinetics. short periods GTP-starting one species. From radioactivity pulse-chase experiments under normal conditions it was found does seem affect stability