Biomaterial Database

Cleavage map of linear mouse sarcoma virus DNA. 1977

E Canaani, and P Duesberg, and D Dina

Proviral DNA transcribed from the RNA of Moloney murine sarcoma virus was isolated from newly infected cells. Three forms of viral DNA were observed: (i) a linear double-stranded form of 3.4 X 10(6) daltons which constituted the major viral DNA species in the cell, and is thought to be a complete transcript (monomer) of viral RNA; (ii) a fast-sedimenting viral DNA bigger than the monomeric unit which can be either integrated provirls or concatamers; and (iii) covalently closed circles of monomer size representing 5% or less of the total viral DNA in the cell. The linear viral DNA was tested for its susceptibility to restriction endonucleases by electrophoretic analysis of the digestion products and their identification by hybridization with viral RNA or cDNA probes. The linear DNA is not cleaved by endonucleases EcoRI and BamHI. It is cleaved into two fragments by endonucleases HindIII and Hae II, and into three fragments by restriction endonuclease HincII. The fragments of the viral DNA added up to approximately 3.4 X 10(6) daltons; this and the uniform size of the linear DNA indicated that the viral DNA has unique ends and a complexity of 3.4 X 10(6) daltons. The different cleavage fragments were ordered with respect to each other and the 3' end of the viral RNA. It was observed that fragments from both ends of the linear DNA can be hybridized to sequence(s) at the 3' end of murine sarcoma virus RNA; this result suggested the possibility that a short redundant sequence exists at both termini of the genome.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D008979	Moloney murine leukemia virus	A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) arising during the propagation of S37 mouse sarcoma, and causing lymphoid leukemia in mice. It also infects rats and newborn hamsters. It is apparently transmitted to embryos in utero and to newborns through mother's milk.	Moloney Leukemia Virus,Leukemia Virus, Moloney,Virus, Moloney Leukemia
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D003673	Defective Viruses	Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.	Incomplete Viruses,Defective Hybrids,Defective Hybrid,Defective Virus,Hybrid, Defective,Hybrids, Defective,Incomplete Virus,Virus, Defective,Virus, Incomplete,Viruses, Defective,Viruses, Incomplete
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D004270	DNA, Circular	Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)	Circular DNA,Circular DNAs,DNAs, Circular
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA