THE CRYPHONECTRIA-PARASITICA PLASMID PUG1 CONTAINS A LARGE ORF WITH MOTIFS CHARACTERISTIC OF FAMILY-B DNA-POLYMERASES

The isolation and characterization of the circular mitochondrial plasm id pUG1 from the ascomycete Cryphonectria parasitica is described. The entire sequence (4182 bp) was obtained and high similarities to DNA-d ependent DNA polymerases were revealed. Strikingly common features wit h the DNA polymerases encoded by the Neurospora intermedia plasmids Fi ji and LaBelle, such as matches to the conserved motifs A and B and th e presence of TTD instead of DTD in motif C, were found, suggesting th e existence of a distinct group of members of the B DNA family polymer ases. These strong similarities between the plasmids might suggest a c ommon origin of the C.parasitica and the Neurospora plasmids.