Index >> Virus Structure and Classification >> Double Stranded DNA (dsDNA)

Double Stranded DNA - dsDNA

It occurs in a variety of forms. "In many animal viruses and bacteriophages (including T4) dsDNA is linear. In T5 the linear duplex has single chain breaks.

In vaccinia the DNA cannot be denatured into two strands, and therefore appear to be cross-linked.

According to one model the linear duplex has closed ends to make one giant circle.

In the papovaviruses (polyoma, SV40) and the phage PM2, the DNA exists in the form of a closed circular duplex, with or without supercoils.