ColE1 cloning of a ribosomal RNA promoter region from lambdarifsup(d)18 by selection for lambda integration and excision functions

The expression of the ribosomal RNA gene carried by the lambda transducing phage lambdarifsup(d)18 is shown to be subject to stringent amino acid control. lambdarifsup(d)18 DNA was digested with endonuclease EcoRI and ligated to similarly restricted ColE1 plasmid DNA. Selection for expression of lambda integration and excision gene activity carried by the same DNA fragment results in cloning of the promoter proximal portion of the 16S ribosomal RNA gene. The resulting chimera expresses lambda integration and excision functions as well as encoding the promoter proximal half of a 16S ribosomal RNA gene. The effect of ultraviolet dose on stringent control of phage lambdarifsup(d)18 dependent ribosomal RNA synthesis is included in the investigation. (Auth.)