FIG. 2.

Agarose gel electrophoresis of restriction digests of HF1 DNA. Lane 1, DNA size standard (HindIII-cut lambda DNA), with fragment sizes indicated at the left. Lane 2, undigested HF1 DNA. Lanes 3 to 6, HF1 DNA cut with DraI, AseI, HpaI, and HindIII, respectively. Arrows point to extra fragments not predicted by the linear genome sequence. R, right terminal restriction fragment; L, left terminal restriction fragment. Some fragments in the lower part of the gel are indicated by white dots. These fragments were also expected from the linear sequence but were faint on the gel, as the ethidium staining intensity decreases with fragment size. Not all terminal fragments were large enough to show on this gel.