Molecular characterization of a new mitovirus hosted by the ectomycorrhizal fungus Albatrellopsis flettii

The complete genome of a novel mycovirus, Albatrellopsis flettii mitovirus 1 (AfMV1), hosted by the basidiomycetous ectomycorrhizal fungus Albatrellopsis flettii (Morse ex Pouzar) Audet, was sequenced and analyzed. The full-length cDNA sequence, obtained from a dsRNA replication intermediate of the AfMV1 genome, is 3037 bp in length with a predicted G+C content of 40.66%. Sequence analysis revealed that a single large open reading frame (ORF) is present on the positive strand when the mold mitochondrial genetic code is applied. The single ORF encodes a putative RNA-dependent RNA polymerase of 859 amino acids with a predicted molecular weight of 97.05 kDa that shares the closest similarity with the corresponding protein of Entomophthora muscae mitovirus 7, with 43.38% sequence identity. Phylogenetic analysis showed that AfMV1 could be classified as a new member of the genus Mitovirus within the family Mitoviridae. This is the first report of the complete genome sequence of a new mitovirus, AfMV1, isolated from the basidiomycetous ectomycorrhizal fungus A. flettii.