The size of the guanosine triphosphate pool as a function of steady state growth rates in Escherichia coli

• Main Author: Ross, John
• Format: Others
• Published: DigitalCommons@Robert W. Woodruff Library, Atlanta University Center 1974
• Subjects: Biology
• Online Access: http://digitalcommons.auctr.edu/dissertations/2098; http://digitalcommons.auctr.edu/cgi/viewcontent.cgi?article=3840&context=dissertations

In an effort to understand how the rate of RNA synthesis is controlled at different steady state growth rates, this investigation has examined the correlation between nucleotide pool size and the rate of total RNA synthesis at different growth rates. Escherichia coli cells were grown in minimal media in chemostats at growth rates corresponding to doubling times of 1.5 and ten hours. The cells were extracted with formic acid and the extract was spotted on polyethyleneimine thin layer chromatography plates. After a two-dimensional development, autoradiographic procedures were used to identify location of nucleotides which were subsequently quantitated by removing the spots and counting. The results of this investigation revealed that there is a 1.66-fold difference in the size of the guanosine triphosphate pool over the growth rate span studied. These results correlate with the 1.7-fold difference in the total rate of RNA synthesis over the same growth span. The results of this paper also support the views that ribosomal RNA is unstable for slow growing cultures and that the control of the three species of RNAs is non-coordinate.