RD-114, baboon, and woolly monkey viral RNAs compared in size and structure (original) (raw)
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Journal of Virology, 1978
Several 50 to 70S tumor viral RNAs have previously been shown by electron microscopy to be dimers, with the two monomer subunits joined near their 5' ends. Five additional naturally occurring type C RNA tumor viruses have now been examined: AKR, and endogenous murine ecotropic virus; NZB, an endogenous murine xenotropic virus; and ecotropic and an amphotropic virus isolated from a wild mouse; and the avian reticuloendotheliosis virus (REV). All five 50 to 70S RNAs have similar 5'-to-5' dimer structures. Therefore, the observations support the hypothesis that the dimer linkage is a structural feature common to all type C mammalian viruses. REV is the first example of an avian virus with a clear 5'-to 5' dimer linkage. All of the mammalian viral RNAs, but not REV, showed symmetrically placed loops in each subunit of the dimer. Possible molecular structures and biological functions of the dimer linkages and loops are discussed.
Physical properties of Rous Sarcoma Virus RNA
Proceedings of the National Academy of Sciences of the United States of America, 1968
The RNA's of several RNA tumor viruses have recently been isolated.1 Two major single-stranded RNA components were obtained, a fast-sedimenting RNA component with a sedimentation coefficient (820,w) of approximately 70S and a slowly sedimenting component of approximately 4S. Since the reported st9 as well as the corresponding molecular weights of the tumor virus RNA's are much larger than those of most other known viral RNA's, a determination of the structure and molecular weight of tumor virus RNA's is of great interest. Knowledge of the structure of tumor virus RNA's may also help to elucidate their replication, which is interrupted by inhibitors of DNA-dependent RNA synthesis such as actinomycin D;2 in addition, no virus-specific double-stranded RNA's have been isolated from infected or transformed cells.
Structure and Molecular Weight of the 60-70S RNA and the 30-40S RNA of the Rous Sarcoma Virus
Proceedings of the National Academy of Sciences, 1974
The structure and molecular weight of the 60-70S RNA complex and the 30-40S RNA species of Rous sarcoma virus were analyzed in an electron microscope after treatment of the RNAs with the bacteriophage T4 gene-32 protein to stretch out the RNA strands. Although all RNA preparations treated with gene-32 protein showed considerable heterogeneity in length, a significant fraction
Molecular weight of RNA subunits of Rous sarcoma virus determined by electron microscopy
Journal of Virology, 1975
Secondary cultures of chicken embryo fibroblasts were infected with the Schmidt Ruppin strain of Rous sarcoma virus (RSV). Five days after infection, the medium was replaced at 2-h intervals with phosphate-free Eagle medium containing 50 muCi of [32P]orthophosphate per ml. Virus was collected by centrifugation, and the RNA was extracted and denatured with dimethyl sulfoxide, and the 33S subunit RNA was isolated by sucrose gradient centrifugation. The molecular weight of the RSV subunit RNA was determined by length measurement in the electron microscope, by using bacteriophage MS2 RNA as a length marker. Molecules of between 2.5 and 3.3 mum in length made up over 50% of the subunit RNA preparation. In this paper, we define RSV RNA subunits as that RNA released from the 70S RNA complex by dimethyl sulfoxide treatment, which sediments as a peak at 33S. Assuming the molecular weight of MS2 RNA to be 1.2 times 10-6, we calculate the molecular weight of RSV subunit RNA to be 3.12 times 10...
Analysis of the secondary and tertiary structures of Rous sarcoma virus RNA
Nucleic Acids Research, 1980
The secondary and tertiary structures of the 35S RNA of Rous Sarcoma virus have been investigated. T-, RNase partial digests have been first resolved into their components by gel electrophoresis under non denaturing conditions and then each component analyzed further by various techniques. More than one hundred structured fragments have thus been isolated and shown to consist of several individual nucleotide sequences located far apart on the genome. On the basis of the results,a cloverleaf model for the structure of RSV 35S RNA is proposed that has implications for the various biological functions of this RNA.
Proceedings of the National Academy of Sciences, 1974
Radioactive DNA ([3HlcDNA) complementary to the RNA of Mason-Pfizer monkey virus was used in molecular hybridization experiments to demonstrate sequence homology between its viral RNA and RNA of human malignant breast tumors. Hybridization products were analyzed by cesium sulfate equilibrium density centrifugation and hydroxylapatite chromatography. Seven of ten human malignant breast tumors tested contained virus-related RNA when assayed by hydroxylapatite chromatography, whereas no sequence homology was found in RNA from 11 human benign breast tumors or from RNA of normal human spleen, liver, or kidney. Hybridizations between [3H]cDNA of the monkey virus and human breast adenocarcinoma RNA showed a Crtl/, of about 2 X 104. The fidelity of the hybrids formed was indicated by a Tm of 80.50.
[The role of structural elements in dimerization of RNA fragments in avian retroviruses]
Molekuliarnaia biologiia
The slipped loop structure, earlier identified as an unusual DNA structure, was found to be a possible element of the RNA folding. In order to experimentally test this suggestion, model oligoribonucleotides capable of forming the SLS were synthesized. Treatment of the oligoribonucleotides with nuclease S1 and RNases specific for single- and double-stranded RNA demonstrated the steric possibility of SLS formation. To determine the possible functional role of SLS-RNA, various naturally occurring RNAs were screened in silico. Among the most interesting findings were dimerization initiation sites of avian retroviral genomic RNAs. Analysis of RNA from 31 viruses showed that formation of the intermolecular SLS during RNA dimerization is theoretically possible, competing with the formation of an alternative hairpin structure. Identification of the secondary structure of selected RNA dimers employing nuclease digestion techniques as well as covariance analysis of the retroviral RNA dimeriza...
Characteristics of two-step RNA dimerization in avian sarcoma and leukosis viruses
Molecular Biology, 2005
Dimerization of two genomic RNA copies is essential for the assembly of retrovirus particles. This process has been studied in detail, and a two-step mechanism has been proposed for the human immunodeficiency virus type 1 (HIV-1). A similar model can be assumed for avian sarcoma and leukosis viruses (ASLV), despite the lack of homology between the dimerization initiation site (DIS) of ASLV and that of HIV-1. The structural features of the ASLV DIS were studied with the examples of the avian leukosis virus HPRS-103 and the avian sarcoma virus CT-10. The rate of spontaneous transition from loose to tight dimers at a higher temperature was studied as dependent on the stem length in the DIS hairpin. Dimers of both types were formed by the selected RNA fragments of the two viruses. The conditions of loose dimer formation differed considerably, although the two viruses had identical sequences (5'-A-CUGCAG-3') of the hairpin loop. Dimerization of CT-10 RNA fragments required an RNA concentration at least an order of magnitude higher than in the case of HPRS-103. The difference was explained by deletion of an adenine from the hairpin stem of C-10.