Alternative RNA degradation pathways by the exonuclease Pop2p from Saccharomyces cerevisiae

Inability of Pop2p to degrade RNA with 3′ phosphate. (A) Reaction scheme for the Pop2p exonuclease reaction on poly(A) substrates containing either 3′-PO₄ or 3′-OH. (B) Representative PAGE for an exonuclease reaction of Pop2p (1200 nM) with A₁₃ (1 nM) with either 3′-PO₄ or 3′-OH. Aliquots were removed at 5, 15, and 60 min. (C) Representative PAGE for an exonuclease reaction of Pop2p (1200 nM) with A₂₄ (1 nM) with either 3′-PO₄ or 3′-OH. Aliquots were removed at 5, 15, and 60 min.