LINEAR MITOCHONDRIAL PLASMIDS OF FUSARIUM-OXYSPORUM CONTAIN GENES WITH SEQUENCE SIMILARITY TO GENES ENCODING A REVERSE-TRANSCRIPTASE FROM NEUROSPORA SPP

Two linear mitochondrial plasmids called pFOXC1 and pFOXC2 from the fu ngus Fusarium oxysporum were previously described. DNA sequence compar isons indicated that the derived amino acid sequences of both plasmids exhibit similarity to the reverse transcriptase of the Mauriceville a nd Varkud plasmids of Neurospora spp. The derived amino acid sequence of pFOXC2 has 51% similarity and 32% identity to the Neurospora revers e transcriptase; sequence similarity was greatest for seven blocks of amino acids that are conserved in reverse transcriptases from a wide r ange of biological sources. Northern analysis suggests that full-lengt h RNAs corresponding to the plasmids are found in representative isola tes.