Transcription units around the gene for E. coli translation initiation factor IF3 (infC)

The coding properties have been analyzed of in vitro constructed lambda recombinant phages carrying E. coli DNA fragments from around the structural gene for translation initiation factor IF3 (infC). This study shows that infC is expressed independently of the promoter of the threonyl-tRNA synthetase (thrS), which is the genes immediately preceding infC. It also shows that the two genes following infC, namely pheS and pheT, which form the phenylalanyl-tRNA synthetase operon, are not expressed from infC's promoter. Thus the four characterized genes of that region that were previously thought to be transcribed in the same direction are now shown to be expressed in vivo as three separate transcription units.