The influence of chloramphenicol on synthesis of ribosomes and beta and beta' subunits of RNA polymerase
Kliachko, E.V.; Perel'man, B.V.; Ponomarenko, O.I.; Shakulov, R.S.
Biokhimiia 42(7): 1278-1284
1977
ISSN/ISBN: 0320-9725 PMID: 332237 Document Number: 110525
The effect of low chloramphenicol concentrations on the biosynthesis of RNA, ribosomal proteins and RNA polymerase in E. coli CP 78 cells was studied. When protein synthesis was decreased by 50--70%, 14C-uracil incorporation in DNA increased twice, the rRNA synthesis being stimulated preferentially. In the presence of antibiotic the RNA/DNA ratio increased from 5,7 to 13,3. The differential rate of r-protein synthesis increased simultaneously with the stimulation of rRNA synthesis, so that alphar rises from 0,083 (without antibiotic) to 0,122 and 0,161 at 5 and 10 microgram/ml of chloramphenicol, respectively. The inhibition of protein synthesis by chloramphenicol is accompanied also by the increase of differential rate of synthesis of beta and beta' subunits of RNA polymerase. In the presence of 5 and 10 microgram/ml of chloramphenicol, alphap increased from 0,90% to 1,44 and 1,57%, respectively. It is assumed that the genes for beta and beta' subunits of RNA polymerase as the ribosomal genes are negatively controlled by guanosine tetraphosphate which intracellular concentration decreased in the presence of chloramphenicol. The known data on the influence of streptolydigin and rifampicin on the RNA polymerase biosynthesis are discussed in view of proposed hypothesis.