Transcription and translation rates

Range Table - link
Organism Bacteria Escherichia coli
Reference Proshkin S, Rahmouni AR, Mironov A, Nudler E. Cooperation between translating ribosomes and RNA polymerase in transcription elongation. Science. 2010 Apr 23 328(5977):504-8. p.505 table 1PubMed ID20413502
Method P.505 left column 2nd paragraph: "To calculate the elongation rate, the Escherichia coli culture was induced with IPTG, and the time that elapsed between the appearance of a specific hybridization signal from probes complementary to the 5' and 3' segments of the lacZ transcript was determined by dotblot hybridization (Fig. 1 and fig. S1) (refs 5, 6)."
Comments P.505 left column top paragraph: "...[researchers] found that for most of the coding region, the first trailing ribosome directly assists RNAP during elongation. Such cooperation between the two macromolecules explains the precise match of translational and transcriptional rates under various growth conditions (Table 1)." P.505 left column 2nd paragraph: "[Researchers] first investigated the effect of the antibiotic chloramphenicol (Cm), a specific inhibitor of translation elongation, on the transcription elongation rate. Cm was added to exponentially growing cells at 1 μg/ml, a concentration that had only a mild inhibitory effect on bacterial growth. In the absence of Cm, the transcription elongation rate was determined to be 42 nucleotides (nt) per second under specified growth conditions, matching a translation elongation rate of 14 amino acids per second (Table 1 and fig. S2). However, Cm reduced the transcription elongation rate to 27 nt/s (Fig. 1B), which matched a reduced translation rate of nine amino acids per s (Table 1 and fig. S2). This result suggests that the ribosome controls the rate of RNAP propagation." See note above table
Entered by Uri M
ID 108487