Insect iridescent virus type 6 encodes a polypeptide related to the largest subunit of eukaryotic RNA polymerase II

HDV Family of Self-Cleaving Ribozymes

“…In one, the ribozyme could serve to inactivate the translation of the large subunit of the polymerase by cleaving the 5 0 cap of the mRNA following the initial production of the subunit during the immediate-early stage of viral infection. 140 Alternatively, drz-CIV-1 might serve to process the polymerase mRNA from the 161 Self-Cleaving Ribozymes surrounding transcript and promote cap-independent translation initiation of the message. The recent discovery of the R2 ribozymes and their proposed roles in translation initiation make the possibility of the latter task more likely, although the in vitro self-cleavage rate in physiological conditions suggests that the majority of the transcripts would be cleaved on a time scale too slow to promote expression of the protein.…”

“…The recent discovery of the R2 ribozymes and their proposed roles in translation initiation make the possibility of the latter task more likely, although the in vitro self-cleavage rate in physiological conditions suggests that the majority of the transcripts would be cleaved on a time scale too slow to promote expression of the protein. 2,3,140 …”

Identification and properties of the largest subunit of the DNA-dependent RNA polymerase of fish lymphocystis disease virus: dramatic difference in the domain organization in the family Iridoviridae

“…1) were synthesized according to the highly conserved regions. RQP(T/S)LH and NADFDGDE of the largest subunit of DdRP from pro-and eukaryotic organisms as described previously (Schnitzler et al, 1994). PCR was performed using 0.01 fmol of FLCDV DNA in 100 ~tl volumes of 50 mM-KC1, 10 mMTri~HC1 pH 8"3, 1-5 mM-MgC12, 0.01% (w/v) gelatin, 200 ~tmol of each dNTP, 1 pmol of each primer and 2.5 units of Taq DNA polymerase (Perkin Elmer).…”

“…DNA-dependent RNA polymerase (DdRP), an essential enzyme for cytoplasmic DNA viruses, has been reported for a variety of poxviruses including vaccinia virus (Moss, 1990), African swine fever virus (Yanez et al, 1993) and insect iridescent virus type 6 (Chilo iridescent virus, CIV) (Schnitzler et al, 1994). DNA-dependent RNA polymerases are complex multisubunit enzymes consisting of two large subunits with a molecular mass of > 100 kDa and several smaller polypeptides which are all present in stoichiometric amounts (Sentenac, 1985).…”

“…Recently we succeeded in identifying and characterizing the gene encoding the largest subunit of the DNA-dependent RNA polymerase of CIV (Schnitzler et al, 1994) by PCR using oligonucleotide primers corresponding to the conserved regions detected within the amino acid sequence of the largest subunit of a variety of pro-and eukaryotic DdRPs. The identification of the gene encoding the largest subunit of the DNA-dependent RNA polymerase of FLCDV using oligonucleotide primers deduced from the conserved domains of the DdRP of pro-and eukaryotic organisms is the subject of the present study.…”