Studies on ribosomal protein biosynthesis in an RNA polymerase temperature sensitive E. coli mutant
✍ Scribed by Pichon, Jacques L. ;Coeroli, Cécile ;Marchis-Mouren, Guy
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 638 KB
- Volume
- 150
- Category
- Article
- ISSN
- 0026-8925
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✦ Synopsis
In E. coli strain XH56 the synthesis of all RNA species is blocked upon shifting the culture to the non-permissive temperature. The decay of specific messenger RNA species coding for individual ribosomal (r) proteins was followed by measuring the rate of r-protein synthesis by pulse labelling at various times after the shift. The half-lives of the average 30S r-protein and 50S r-protein mRNA species are identical (1.75 min) and shorter than those of the average messenger coding for total cell proteins (2.75 min). Most individual r-protein messengers have a half-life in the same range (1.50-2.00). Only a few r-protein messengers have significantly longer half-lives: S1 (2.80 min), S17 (3.29 min), L29 (2.30 min), L31 (2.30 min), L32 (2.33 min) and L16 (2.60 min). The results indicate that the degradation of most individual r-protein mRNA species is not specifically controlled. After a few min at the non-permissive temperature, all protein synthesis is blocked. The restart of r-protein synthesis was followed after shifting the culture back to the permissive temperature. The recovery of cell growth is very slow. During this period preferential r-protein synthesis was observed. Moreover differential rates of bisynthesis of r-proteins was obtained, it may be indicative of specific regulatory process(es).