Lifson, E. R.Lindahl, L.Zengel, J. M.2019-06-052019-06-051986-02E R Lifson, L Lindahl, and J M Zengel, Precursor for elongation factor Tu from Escherichia coli, J Bacteriol. 1986 Feb; 165(2): 474–482, DOI: 10.1128/jb.165.2.474-482.1986https://doi.org/10.1128/jb.165.2.474-482.1986http://hdl.handle.net/11603/14017The tufA gene, one of two genes in Escherichia coli encoding elongation factor Tu (EF-Tu), was cloned into a ColE1-derived plasmid downstream of the lac promoter-operator. In cells carrying this plasmid, the synthesis of EF-Tu was increased four- to fivefold upon the addition of isopropyl-beta-D-thiogalactopyranoside (an inducer of the lac promoter). This condition led to the synthesis of a novel protein, called pTu, which comigrated with EF-Tu on a sodium dodecyl sulfate-polyacrylamide gel but could be separated on an isoelectric focusing gel, since pTu is slightly more basic than EF-Tu. The synthesis of pTu could also be induced by the synthesis of a hybrid protein containing just the amino-terminal half of the EF-Tu protein. Genetic data suggest that pTu is the product of the tufA and tufB genes. The pTu protein was shown to be related to EF-Tu by gel electrophoresis of tryptic peptides. Pulse-chase experiments suggest that pTu is a precursor of EF-Tu. Interestingly, in a classic membrane fractionation procedure, EF-Tu was found in the cytosolic fraction, whereas pTu was partitioned with the outer membrane.9 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.elongation factor TuEscherichia coliisopropyl-beta-D-thiogalactopyranosideText