“Delayed-Early” mRNA for the Tryptophan Operon? An Effect of Chloramphenicol
This extract was created in the absence of an abstract.
Excerpt
Messenger RNA (mRNA) from the tryptophan operon of E. coli is synthesized, translated, and degraded in a closely coordinated manner. Ribosomes travel along the nascent messenger closely behind the RNA polymerase; the messenger is then degraded (5′ → 3′) immediately after passage of the last ribosome (Morse, Mosteller, and Yanofsky, 1969). The sequential synthesis and degradation of mRNA for the trp operon (gene order = O-E-D-C-B-A) is observed in Fig. 1A.
If chloramphenicol (100 °g/ml) is added to a culture of E. coli when the newly synthesized trpE mRNA is being traversed by ribosomes, this mRNA is protected from degradation; however, the appearance of more distal regions of trp mRNA cannot be detected (Fig. IB). Similarly, if chloramphenicol is added soon after synthesis of D mRNA, appearance of the more distal C, B, and A mRNA is not observed. The effect of chloramphenicol upon distal mRNA is presumably specific for...
