A Bent Helix in Kinetoplast DNA
This extract was created in the absence of an abstract.
Excerpt
Kinetoplast DNA, the mitochondrial DNA in trypanosomes, Leishmania, and related protozoa, has a remarkable structure. It consists of thousands of DNA circles interlocked in a massive network (Fig. 1) (for review, see Simpson 1972; Borst and Hoeijmakers 1979; Barker 1980; Englund 1981; Englund et al. 1982). Each cell contains only one network within its single mitochondrion. Networks are composed of two kinds of DNA circles. There are roughly 25 maxicircles that contain the usual gene complement typical of mitochondrial DNAs. These vary from 20 kb to 40 kb, depending on the species. Most of the network consists of minicircles. There are 5000–10,000 minicircles in a network, and, depending on the species, they vary from 0.7 kb to 2.5 kb. Within a network, all of the minicircles are the same size, although they are generally heterogeneous in sequence. They do not appear to be transcribed and their function is not known....
