pubmed:abstractText |
A previously isolated thermosensitive mutant [Springer, M., Graffe, M. & Grunberg-Manago, M. (6977) Mol. Gen. Genet. 151, 17-26] exhibits two defects in vitro, one in the initiation factor IF3 and the other in the L-phenylalanine: tRNA-Phe ligase (EC 6.1.1.20). Specialized lambda transducing phages that transduced this mutant to thermoresistance were selected. In vitro studies showed that the transductants had a normal IF3 activity. One of these transducing phages was shown to code for a protein synthesized under the control of Escherichia coli promoters, which has the same molecular weight as IF3. This protein crossreacts specifically with IF3 antisera and comigrates with pure IF3 in a two-dimensional gel system.
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