Restriction enzyme cleavage mapping of T7 virus early region.

DNA molecules of seven T7 mutants with overlapping deletions in the early region were cleaved by restriction enzymes HindII, HpaI and II, and HaeIII. The differences in the cleavage patterns after electrophoresis have been used to generate a cleavage map of the restriction sites of this enzyme. It covers the first 9% of the T7 DNA molecule. Cleavage points for HindII are at 0.60, 1.33, 1.59, 1.76, 5.26, 6.27, 7.4 and 8.38%; for HpaI and II at 1.36, 1.62, 4.46, 6.29, 6.62, 7.56, and 8.76%, for HaeIII at 3.85, 6.98, 7.88 and 8.26%. Some fragments have been located in the region containing the early promoters, others carry the complete sequences of gene 0.3.