Synthesis and maturation of ribosomal RNA in Escherichia coli.

摘要: Abstract A high resolution autoradiographic technique has been developed for the quantitative analysis of distribution 14 C-labeled RNA on polyacrylamide gels after electrophoresis. We have used this to study synthesis and maturation ribosomal in Escherichia coli obtained following results: 1. (1) There exist one or perhaps two precursors 16 s detectable precursor 23 RNA, each slightly lower electrophoretic mobilities than mature forms. The precursor-product relationships are proven by accurate kinetic experiments, pulse-chase experiments and, most convincingly, demonstration that takes place when further is inhibited actinomycin D. 2. (2) Protein inhibition chloramphenicol treatment methionine starvation stringent cultures inhibits causes accumulation large amounts these precursors. which accumulates methionine-starved converted forms restored. 3. (3) kinetics 5 essentially first order hence do not provide evidence existence a pool macromolecular s. This corroborated show there only negligible increase label if D added culture pulsed minutes with 4. (4) s-like mobility normal chloramphenicol-inhibited cultures. species also matures upon restoration starved culture. produced nucleolytic cleavage molecular weight during its since coupled either No other can be detected E. exponential growth protein inhibition. 5. (5) Ribosomal synthesized period recovery from starvation, contrary conclusions Nakada, Anderson & Magasanik (1964). However, long delay appearance presumably due dilution newly-synthesized radioactive “relaxed” accumulated period.