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.
