ABSTRACT
The interactions between Rous Sarcoma virus (RSV) RNA and the viral proteins in the virus have been analysed by Sen & Todaro (1977) using ultraviolet light irradiation; they showed that the major protein ultraviolet light cross-linked to the viral RNA was P19 as identified by polyacrylamide gel electrophoresis. We report here that it is not viral protein P19 but P12 that binds tightly to RSV RNA upon ultraviolet light irradiation of the virus. Therefore, the binding sites of the viral protein along RSV RNA that we have characterized previously should be correctly attributed now to P12 and not P19.
Subject(s)
Avian Sarcoma Viruses/analysis , RNA, Viral/metabolism , Viral Proteins/metabolism , Avian Sarcoma Viruses/radiation effects , Binding Sites , Electrophoresis, Polyacrylamide Gel , Phosphoproteins/metabolism , Ultraviolet Rays , Viral Core ProteinsSubject(s)
Alpharetrovirus/radiation effects , Avian Leukosis Virus/radiation effects , Avian Sarcoma Viruses/radiation effects , Moloney murine leukemia virus/radiation effects , Avian Sarcoma Viruses/growth & development , Cell Transformation, Neoplastic/radiation effects , Cell Transformation, Viral/radiation effects , Gamma Rays , RNA, Viral/radiation effects , Ultraviolet Rays , Vesicular stomatitis Indiana virus/radiation effectsSubject(s)
Avian Sarcoma Viruses/genetics , DNA, Viral/biosynthesis , Genes, Viral , Animals , Avian Sarcoma Viruses/metabolism , Avian Sarcoma Viruses/radiation effects , Cell Transformation, Viral , Cells, Cultured , Chick Embryo , Clone Cells , DNA, Viral/genetics , Fibroblasts , Mutation , Quail , Species Specificity , Ultraviolet Rays , Virus ReplicationABSTRACT
An electron microscopic method for demonstrating the presence of and mapping the positions of proteins specifically bound to nucleic acids is described. The nucleic acid-protein complex is treated with dinitrofluorobenzene under conditions such that dinitrophenyl (DNP) groups are attached to nucleophilic groups on the protein, with only a low level of random attachment to the nuclei acid. This product is treated with rabbit anti-DNP IgG. The position of the protein-(DNP)n(IgG)m complex on the nucleic acid strand can be observed by electron microscopy by protein free spreading methods and, in many cases, by cytochrome-c spreading. If necessary for visualization by the latter method, the size of the labeled region can be increased by treatment with goat anti-rabbit IgG. High efficiency of electron microscopic labeling is achieved. Examples studied are: the adenovirus-2 DNA terminal protein, a protein covalently bound to SV40 DNA, DNA polymerase I bound to DNA, E. coli RNA polymerase bound to T7 DNA, and proteins UV crosslinked to avian sarcoma virus RNA.
Subject(s)
DNA, Viral/metabolism , Microscopy, Electron/methods , Viral Proteins/metabolism , Adenoviruses, Human , Avian Sarcoma Viruses/radiation effects , Binding Sites , Coliphages/enzymology , DNA-Directed RNA Polymerases/metabolism , Immunologic Techniques , Simian virus 40 , Ultraviolet RaysSubject(s)
Avian Sarcoma Viruses/radiation effects , Ultraviolet Rays , Avian Sarcoma Viruses/metabolism , Cell Transformation, Neoplastic/radiation effects , DNA, Viral/biosynthesis , Defective Viruses/radiation effects , Fibroblasts , Kinetics , Nucleic Acid Hybridization , RNA, Viral/biosynthesis , Virus Replication/radiation effectsABSTRACT
Purified preparations of Rous sarcoma virus (an avian tumor virus with an RNA genome) contain small amounts of double-stranded DNA. This DNA cannot be hybridized to viral RNA, but will reanneal completely with the DNA of avian cells. Extensive substitution of bromodeoxyuridine for thymidine in "viral" DNA does not photosensitize the biological activity of the virus. These observations indicate that the DNA associated with Rous sarcoma virus is derived from the DNA of the avian host cell, and is probably devoid of any function in the life cycle of the virus.
