Replication of linear mitochondrial DNA from Paramecium: sequence and structure of the initiation-end crosslink.
Replication of the 14-micrometer linear Paramecium mitochondrial DNA is initiated by a crosslinking of the duplex strands at the initiation end of the molecule. As a consequence of the crosslink, a head-to-head dimer molecule, or palindrome, is a replicative intermediate. The central region of the dimer molecules of two species was cloned and sequenced, In the distal regions, the sequence is palindromic as expected; however, in the central region, there is a nonpalindromic sequence that is rich in A + T and contains direct tandem repeats. It is proposed that the nonpalindromic sequence constitutes the crosslink. Implications for the replication scheme are discussed. The model is unlike any other for a linear DNA.
D000818:Animals; D001483:Base Sequence; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000235:genetics*; D010247:Paramecium / Q000235:genetics*
D004272:DNA, Mitochondrial