A mutation in the RNA polymerase β′ subunit causing depressed ribosomal RNA synthesis in Escherichia coli

1981 ◽  
Vol 183 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Ben A. Oostra ◽  
Klaas Kok ◽  
Adri J. Van Vliet ◽  
AB Geert ◽  
Max Gruber
1970 ◽  
Vol 117 (3) ◽  
pp. 623-631 ◽  
Author(s):  
Volker Neuhoff ◽  
Wolf-Bernhard Schill ◽  
Hans Sternbach

By using micro disc electrophoresis and micro-diffusion techniques, the interaction of pure DNA-dependent RNA polymerase (EC 2.7.7.6) from Escherichia coli with the template, the substrates and the inhibitors heparin and rifampicin was investigated. The following findings were obtained: (1) heparin converts the 24S and 18S particles of the polymerase into the 13S form; (2) heparin inhibits RNA synthesis by dissociating the enzyme–template complex; (3) rifampicin does not affect the attachment of heparin to the enzyme; (4) the substrates ATP and UTP are bound by enzyme loaded with rifampicin; (5) rifampicin is bound by an enzyme–template complex to the same extent as by an RNA-synthesizing enzyme–template complex. From this it is concluded that the mechanism of the inhibition of RNA synthesis by rifampicin is radically different from that by heparin. As a working hypothesis to explain the inhibitory mechanism of rifampicin, it is assumed that it becomes very firmly attached to a position close to the synthesizing site and only blocks this when no synthesis is in progress.


Weed Science ◽  
1972 ◽  
Vol 20 (4) ◽  
pp. 364-366 ◽  
Author(s):  
Donald Penner ◽  
Roy W. Early

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 10−5M applied to etiolated corn(Zea maysL. ‘Michigan 500′) seedlings 6 or 12 hr before the isolation of chromatin from the roots markedly reduced ribonucleic acid (RNA) synthesis supported by the chromatin. The addition ofEscherichia coliRNA polymerase failed to overcome the inhibition. Trifluralin increased the melting temperature of the chromatin. The presence of trifluralin during the isolation and reaction procedure inhibited RNA synthesis indicating possible trifluralin binding to the chromatin with subsequent reduction of template availability for transcription. Trifluralin did not inhibit chromatin activity in soybean [Glycine max(L.) Merr. ‘Hark’] seedlings.


1986 ◽  
Vol 203 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Robert E. Glass ◽  
Steven T. Jones ◽  
Akira Ishihama

FEBS Letters ◽  
1983 ◽  
Vol 153 (2) ◽  
pp. 420-426 ◽  
Author(s):  
Tamata Kutateladze ◽  
Robert Beabealashvili ◽  
Alexey Azhayev ◽  
Alexander Krayevsky

1967 ◽  
Vol 3 (2) ◽  
pp. 183-193 ◽  
Author(s):  
E. Fuchs ◽  
R. L. Millette ◽  
W. Zillig ◽  
G. Walter

1982 ◽  
Vol 188 (3) ◽  
pp. 399-404 ◽  
Author(s):  
Vishvanath Nene ◽  
Robert E. Glass

1978 ◽  
Vol 56 (6) ◽  
pp. 528-533 ◽  
Author(s):  
Stephen M. Boyle ◽  
Frederick Chu ◽  
Nathan Brot ◽  
Bruce H. Sells

The level of ppGpp and rates of synthesis of stable RNA, ribosomal protein, and the β and β′ subunits of RNA polymerase were measured following a nutritional shiftup in Escherichia coli strains, NF 929 (spoT+) and NF 930 (spoT'−). In the spoT+ strain, ppGpp levels decreased 50% within 2 min following shiftup, and the rates of synthesis of stable RNA, ribosomal proteins, and the β and β′ subunits of RNA polymerase increased with little or no lag. In contrast, in the spoT− strain, ppGpp levels transiently increased 40% during the first 6 min following shiftup. An inhibition in the rate of stable RNA synthesis and a delay in the increased synthesis of ribosomal proteins and β and β′ subunits occurred concurrently with the transient increase in ppGpp. In addition, the DNA-dependent synthesis in vitro of the β and β′ subunits of RNA polymerase was inhibited by physiological levels of ppGpp. Because of the timing and magnitude of the changes in ppGpp levels in the spoT− strain versus the timing when the new rates of stable RNA, ribosomal protein, and β and β′ subunits synthesis are reached, it is concluded that ppGpp is not the sole element regulating the expression of these genes.


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