Structure of a Cephalosporium acremonium mtDNA replicator

We have investigated the ARS (autonomously replicating sequence) activity of a 1.94 kb mitochondrial DNA fragment of Cephalosporium acremonium and found that several subfragments of this piece of mtDNA conferred the ARS phenotype. The nucleotide sequence of the fragment shows: (i) a high A + T content (72.5%); (ii) a perfect consensus ARS sequence (ATTTATATTTA) in the subfragment with the highest ARS activity; (iii) a large number of ARS consensus-related sequences in the other subfragments, even in one lacking ARS activity; (iv) several potential hairpin structures. One of them contains the perfect consensus ARS sequence.