[Expression of the restriction fragment of phage T7 DNA in a cell-free transcription-translation system from E. coli].

The matrix activity of phage T7 DNA and the restriction fragment of phage T7 DNA containing gene 0,3 with a promoter was studied with respect to RNA and protein syntheses in a cell-free transcription-translation system from E. coli. A comparison of the protein products of cell-free synthesis was carried out, using polyacrylamide gel electrophoresis and a subsequent radiofluorography. Data from PAAG suggest that the restriction fragment codes the synthesis of a polypeptide, whose size is identical to that of a polypeptide synthesized on a corresponding gene in phage T7 DNA. A possible use of the cell-free system of coupled transcription-translation for the functional mapping of the genome DNA is discussed.