Abstract
The concentration of elongation factor Tu(EF-Tu) is about 8 times that of ribosomes in extracts of E. coli B grown in glucose-minimal medium. Of the EF-Tu, 90% is found in the ribosome-free fraction of the cell and 75% of this is free of other macromolecules as judged by chromatography on Sephadex G-100; about 10% is bound to the elongation factor EF-Ts and the remaining 10-15% is eluted from Sephadex G-100 earlier than expected for its MW. Tryptic peptide maps of the 3 forms of EF-Tu are essentially indistinguishable.