RNA polymerase activity in purified virions of avian reticuloendotheliosis viruses

Abstract

An RNA polymerase activity that synthesizes a U-rich RNA hydrogen bonded to a large viral RNA molecule was found in the cores of virions of avian reticuloendotheliosis viruses (REV). The RNA polymerase activity was separable from the DNA polymerase activity of REV virions. The 5'-terminus of the newly synthesized RNA was A. In addition, a tRNA nucleotidyl transferase activity, which added -CpCpA ends to tRNA, appears to be present in the REV virions.previously (16).Isotopes and other chemicals. All 3H-and a-32Plabeled ribonucleoside triphosphates and most [y-32P]ATP were purchased from New England Nuclear Corp. (Boston, Mass.). Part of the experiments were carried out with [y-32P]ATP that was a kind gift of J. Miller. [y-32P]GTP and [y-32P]UTP were purchased from Amersham/Searle (Arlington Heights, Ill.). Unlabeled ribonucleoside triphosphates, diphosphates, and monophosphates, RNase T2, and Pronase were purchased from Calbiochem (San Diego, Calif.). Torula RNA was purchased from P-L Biochemicals (Milwaukee, Wis.) and was further purified by phenol extraction before use. Actinomycin D was a kind gift of Merck, Sharp and Dohme Research Laboratories. a-Amanitin was purchased from C. H. Boehringer Sohn (New York, N.Y.). Polyethyleneimine-cellulose and cellulose MN300 thin-layer plates were purchased from Brinkmann Instruments (Westburg, N.Y.).Conditions for RNA synthesis. Purified REV virions were disrupted with 0.25% (final concentration) Nonidet P-40 in 0.02 M Tris-hydrochloride, pH 8.0, containing 0.005 M dithiothreitol and 0.0008 M 610 on July 6, 2020 by guest

Ribonucleotides in unintegrated linear spleen necrosis virus DNA

“…Alternatively, the SNV RNA-dependent DNA polymerase may have other primer requirements. The RNA polymerase activity detected in reticuloendotheliosis virus virions (26) may be responsible for the generation of these primers.…”

Formation of reticuloendotheliosis virus pseudotypes of Rous sarcoma virus

“…The inability of the a form of BH-RSV to utilize the SNV polymerase may be due to the lack of proper primer molecules, that is, the primer molecule normally used by SNV. Mizutani and Temin have postulated that an RNA polymerase found in SNV virions may be responsible for synthesis of an RNA primer on SNV 70S RNA prior to DNA synthesis (21,22). Alternatively, the lack of complementation may be due to physical differences between REV and ALSV polymerases.…”

“…Alternatively, the lack of complementation may be due to physical differences between REV and ALSV polymerases. The SNV polymerase consists of a single polypeptide of about 70,000 daltons, intermediate in size between the two subunits of the ALSV polymerase (22). Thus, if the polymerase molecule plays some structural role in the core, the significant difference in sizes may preclude the incorporation of SNV polymerase into BH-RSVa virions or formation of a functional enzyme-primer-70S RNA complex.…”