A gap at a unique location in newly replicated kinetoplast DNA minicircles from Trypanosoma equiperdum

Abstract

Kinetoplast DNA is a network containing thousands of interlocked minicircles. The minicircles replicate as free molecules after release from the network, and their progeny are then reattached (Englund, P. T., (1979) J. Biol. Chem. 254, 4895-4900). In Trypanosoma equiperdum, some of the newly replicated minicircles which have recatenated to the network contain a single gap. This gap is about 10 nucleotides in size and it is in the newly synthesized strand. Based on several criteria (S1 nuclease digestion, denaturing polyacrylamide gel analysis and DNA sequencing), the gap residues at a unique site on the molecule. This site overlaps the sequence GGGGTTGGTGTAA, which is the only common sequence found in all minicircles, from several different species, which have been examined.