id author title date pages extension mime words sentences flesch summary cache txt cord-275403-g4rohhtt Bautista, Elida M. Functional Properties of the Predicted Helicase of Porcine Reproductive and Respiratory Syndrome Virus 2002-07-05 .txt text/plain 7432 401 48 To examine characteristics of putative nonstructural proteins (nsp) encoded in ORF1b, which have been identified by nucleotide similarity to domains of equine arteritis virus, defined genomic regions were cloned and expressed in the pRSET expression system. As initial proof of helicase-like activity, experiments were performed to test the ability of purified PRRSV-14 nsp10 protein to hydrolyze radiolabeled ribonucleotides in the presence or absence of polyribonucleotides. To further analyze the predicted helicase activity of the PRRSV nsp10 protein, experiments were performed using duplex substrates prepared with synthetic oligonucleotides containing single-strand regions at the 3Ј or 5Ј ends and short duplex regions (21 and 24 bp). The 5Ј-to-3Ј orientation of the unwinding activity of the PRRSV helicase was further confirmed in experiments using substrates prepared with in vitro transcribed RNA that contained singlestrand regions at the 5Ј end of both strands and duplex regions of 67 bp (5Ј5ЈDuplex #1) and 85 bp (5Ј5ЈDuplex #2), as shown in Fig. 9B . ./cache/cord-275403-g4rohhtt.txt ./txt/cord-275403-g4rohhtt.txt