Basidiomycetous fungus Flammulina velutipes harbors two linear mitochondrial plasmids encoding DNA and RNA polymerases

Basidiomycetous fungus Flammulina velutipes R15 strain had two linear plasmids in its mitochondria designated pFV1 and pFV2. They were double-stranded DNAs, whose sizes were 8.3 and 8.9 kb, respectively. Sequencing analysis of 7364 bases of the pFV1 and 6861 bases of the pFV2 revealed that the both plasmids had one set of two open reading frames (ORFs) each of that encoded putative DNA and RNA polymerases similar to those of mitochondrial plasmids in other filamentous fungi. In phylogenetic analysis of deduced amino acid sequences of the ORFs and counterparts of other filamentous fungi, the pFV2 was expectedly clustered with plasmids of basidiomycetous fungi. whereas the pFV1 with kalilo plasmid of ascomycetous fungus Neurospora intermedia.