Number of Initiation Factor 3 IF3 molecules per ribosome

Value 0.2 molecules/ribosome Range: Table - link molecules/ribosome
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 Table 4
Primary Source Howe JG, Hershey JW. Initiation factor and ribosome levels are coordinately controlled in Escherichia coli growing at different rates. J Biol Chem. 1983 Feb 10 258(3):1954-9PubMed ID6337147
Method Cells were grown in media containing [35S]sulfate and different carbon sources, and harvested during mid-exponential phase after about 10 generations of balanced growth. Initiation factors (IF), elongation factors (EF), and a number of ribosomal proteins were identified unambiguously in gel patterns following two-dimensional polyacrylamide gel electrophoresis.
Comments In E. coli IF3 is required for the 30S subunit to bind to the initiation site in mRNA. In addition, it has several other jobs including the stabilization of free 30S subunits, enables 30S subunits to bind to mRNA and checks for accuracy against the first aminoacyl-tRNA.
Entered by Uri M
ID 104064