Saccharomyces cerevisiae RNA lariat debranching enzyme, Dbr1p, is required for completion of reverse transcription by the retrovirus-like element Ty1 and cleaves branched Ty1 RNAs.

摘要: RNA debranching enzymes are 2'-5' phosphodiesterases found in all eukaryotes. Their main role is cleavage of intron lariat branch points, promoting turnover via exonucleases. Consistent with this role, cells reduced enzyme activity accumulate lariats. The Saccharomyces cerevisiae Dbr1p also a host factor for the yeast long terminal repeat (LTR) retrotransposon Ty1, model many aspects retroviral replication. Fittingly, human Dbr1 immunodeficiency virus, HIV-1. and act at reverse transcription stages Ty1 HIV-1, respectively. Although efficient production full-length cDNA requires Dbr1p, findings reported here indicate that earliest distinct product, minus strand strong stop DNA (-sssDNA), equivalent wild type dbr1∆ mutant cells. Several branched RNAs shown to during retrotransposition. These data consistent creation branches prior their removal by allow extension early products. support possibility formation play broadly shared, but unknown roles LTR transcription.