Fraction of active ribosomes

Value 0.8 unitless
Organism Bacteria Escherichia coli
Reference Bremer, H., Dennis, P. P. (1996) Modulation of chemical composition and other parameters of the cell by growth rate. Neidhardt, et al. eds. Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology, 2nd ed. chapter 97 p.2 Table 1
Primary Source [57] Forchhammer J, Lindahl L. Growth rate of polypeptide chains as a function of the cell growth rate in a mutant of Escherichia coli 15. J Mol Biol. 1971 Feb 14 55(3):563-8.PubMed ID4927947
Method Primary source p.563 bottom paragraph: "The fraction of ribosomes which are actively engaged in peptide synthesis at a given moment was estimated by sucrose gradient analysis, assuming that all ribosomes in polysomes are active."
Comments P.2 bottom paragraph: "In Table 1, a number of growth-related parameters are listed that are generally useful in describing or establishing the macromolecular composition of bacterial cultures. These parameters can be divided into five classes: (i) structural parameters that are inherently constant and do not vary with the growth rate, like the number of rRNA nucleotides in a 70S ribosome, (ii) partition factors which are essentially invariant and growth rate independent, like the fraction of total RNA that is stable rRNA, (iii) other partition parameters which change as a function of the exponential growth rate and have substantial effects on cell composition, like the fraction of active RNA polymerase synthesizing rRNA and tRNA, (iv) kinetic parameters describing functional activities (the values of some of the parameters are essentially invariant, whereas others appear to approach a maximum or biological limit value, like the peptide chain elongation rate), (v) chromosome replication and cell division parameters that in general do not limit the exponential growth rate, like the C period." The bacterial strain used was E. coli 15 TAU-bar
Entered by Uri M
ID 102344