Restriction digests of the clone give the following sizes (kb): BamHI--6.6; EcoRI--5.4, 1.1, 0.4; HindIII--6.6. The presence of the terminator upstream of the cloning sites of the polylinker prevents transcription that starts at cryptic promoters in the vector sequence. This is a promoter cloning vector suitable for studying transcriptional activity of very weakly active promoter fragments. This was constructed by inserting a 1.025 kb SalI fragment from pUMSSB1 containing the strong transcription terminator from the mouse c-mos gene (UMS = upstream mouse sequence) into the EcoRI site of pEMBL8-CAT using EcoRI linkers. |