Origin and Direction of Simian Virus 40 Deoxyribonucleic Acid Replication

Fareed, George C.; Garon, Claude F.; Salzman, Norman P.

doi:10.1128/jvi.10.3.484-491.1972

Cited by 253 publications

(36 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of course, when viewing a linear molecule in the electron microscope one cannot tell "right" from "left," so the designation of unreplicated branches as Li and L2 must be arbitrary. We have employed the convention originally used by Fareed et al (8) of assigning the shortest unreplicated branch of a given molecule as L, and designated this "short arm" as the left-hand end of the molecule in all cases.…”

Section: Resultsmentioning

confidence: 99%

“…Perhaps the most unique feature of RSF1040 is that its overall replication is asymmetric and bidirectional. In other DNA species known to undergo bidirectional replication, such as simian virus 40 (8), polyoma (1), and E. coli (17), the bidirectional replication is symmetrical and the two replication forks reach the termination point at roughly the same time. In the case of RSF1040, however, the replication from the a origin is sequential in the sense that replication first proceeds to a unique terminus in one direction and then proceeds from the origin in the other direction to the terminus to complete the replicative process.…”

Section: Downloaded Frommentioning

confidence: 99%

See 1 more Smart Citation

Mode of replication of the conjugative R-plasmid RSF1040 in Escherichia coli

Crosa¹,

Luttropp²,

Falkow³

1976

J Bacteriol

View full text Add to dashboard Cite

Replicating deoxyribonucleic acid (DNA) molecules of plasmid RSF1040, a deletion mutant of the conjugative R plasmid R6K, appear in the electron microscope as partially supercoiled structures with two open circular branches of equal size, although open structures with three branches, two branching points, and no supercoiled regions (0 structures) were also found at a lower frequency. The partially supercoiled molecules sediment more rapidly than native covalently closed circular DNA in neutral sucrose gradients and band at a position intermediate between covalently closed circular and open circular DNA in CsClethidium bromide gradients. Electron microscope measurements of the linear EcoRI-treated replicative intermediates indicate that replication can be initiated at two sites (origins) on the plasmid DNA molecule located at about 23% (a) and 39% (,8) of the total genome length from an EcoRI end designated arbitrarily as the "left-hand" end of the molecule. The overall replication of RSF1040 is asymmetrically bidirectional. Replication from the a origin proceeds first to the "tright" to a unique termination site located some 55% of the total genome length from the left-hand end of the molecule. At this point replication proceeds from the a origin to the "left" (i.e., opposite to the original direction of replication) until replication of the molecule is completed. Replication also proceeds from the , / origin asymmetrically to the unique terminus site. 454 on August 3, 2020 by guest

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Downloaded Frommentioning

confidence: 99%

Mode of replication of the conjugative R-plasmid RSF1040 in Escherichia coli

Crosa¹,

Luttropp²,

Falkow³

1976

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…The genome of simian virus 40 (SV40) consists of two gene segments, designated "early" and "late," separated by a control region containing start sites for early and late gene transcription (1,18,19,21,23,30,42), and the origin (ori) of DNA replication (12,15,51). The temporal distinction is based on events that occur during the lytic cycle in permissive cells; early functions are those expressed before the onset of viral DNA replication.…”

mentioning

confidence: 99%

Simian virus 40 mutant with transposed T-antigen and VP1 genes

Lazarowitz¹

1982

J Virol

View full text Add to dashboard Cite

A simian virus 40 mutant with the T-antigen gene transposed to the late region of the viral genome has been constructed. This transposed molecule directed the synthesis of a full-sized, 92,000-dalton large T antigen in both permissive and nonpermissive cells. This large T antigen functioned in the initiation of viral DNA replication and in the transformation of nonpermissive cells. T-antigen synthesis by this transposed genome had the characteristics of late transcription, thus indicating that functional large T antigen of simian virus 40 is not required for the initiation of late transcription.

show abstract

“…The tumor antigen (T-antigen) of simian virus 40 (SV40), encoded by the viralA gene (1,18,23,24,32), binds to SV40 DNA (3) and is required for the initiation of viral DNA synthesis (4,31). DNA replication is initiated at a unique site located 0.67 fractional unit from the EcoRI site on the conventional physical map of SV40 (11). Curiously, however, T-antigen binds with high affinity to three different HindII + HI restriction fragments of SV40 DNA, only one of which includes the origin of DNA replication (16).…”

mentioning

confidence: 99%

Interaction of Simian Virus 40 chromatin with Simian Virus 40 T-antigen

Persico-Dilauro¹,

Martin²,

Livingston³

1977

J Virol

View full text Add to dashboard Cite

We have studied the binding of the tumor antigen (T-antigen) of simian virus 40 to simian virus 40 chromatin (minichromosomes). The minichromosomes isolated from infected cells by a modification of standard techniques were relatively free of contaminating RNA and cellular DNA and had a ratio (by weight) of protein to DNA of approximately 1; their DNA was 50 to 60% digestible to an acid-soluble form by staphylococcal nuclease. Cleavage of this chromatin with restriction endonucleases indicated that the nuclease-resistant regions were randomly distributed in the population of minichromosomes, but were not randomly distributed within minichromosomes. Only 20 to 35% of these minichromosomes adsorbed nonspecifically to nitrocellulose filters, permitting binding studies between simian virus 40 T-antigen and chromatin to be performed. Approximately two to three times as much T-antigen was required to bind chromatin as to bind an equivalent amount of free DNA. When T-antigen was present in excess, both chromatin and free DNA were quantitatively retained on the filters. On the other hand, when DNA or chromatin was present in excess, only one-third as much chromatin as DNA was retained. We suggest that T-antigen-chromatin complexes may be formed by the cooperative binding of T-antigen to chromatin, whereas T-antigen-DNA complexes may be formed by simple bimolecular interactions.The tumor antigen (T-antigen) of simian virus 40 (SV40), encoded by the viralA gene (1,18,23,24,32), binds to SV40 DNA (3) and is required for the initiation of viral DNA synthesis (4, 31). DNA replication is initiated at a unique site located 0.67 fractional unit from the EcoRI site on the conventional physical map of SV40 (11). Curiously, however, T-antigen binds with high affinity to three different HindII + HI restriction fragments of SV40 DNA, only one of which includes the origin of DNA replication (16). We have therefore examined the interaction of Tantigen with SV40 chromatin to determine whether the condensation of DNA into chromatin affected its capacity to bind T-antigen.It has been demonstrated that the histones of SV40 chromatin isolated from infected cells (9, 12) or from visions (5) are condensed into 21 spherical units or v-bodies. It is presumably these structures that result in the failure of staphylococcal nuclease to digest completely all ofthe DNA ofchromatin. Polisky and McCarthy (26) have argued that the protected regions are randomly distributed along the DNA; however, the chromatin they studied was prepared from virions by a technique that disrupts the v-bodies (5). We have therefore reexamined the distribution of the protected regions preparatory to the study of T-antigen binding to chromatin. MATERIALS AND ME]HODSCell growth. BSC-1 monkey kidney cells were grown in 75-cm2 tissue culture flasks (Falcon Plastics, Oxnard, Calif.) or 700-cm2 glass roller bottles in Eagle minimal essential medium (MEM; NIH Media Supply) supplemented with 2% (MEM-2) or 10% (MEM-10) fetal bovine serum (Flow Laboratories, Inc., Rockville, Md.) in ...

show abstract

Origin and Direction of Simian Virus 40 Deoxyribonucleic Acid Replication

Cited by 253 publications

References 16 publications

Mode of replication of the conjugative R-plasmid RSF1040 in Escherichia coli

Mode of replication of the conjugative R-plasmid RSF1040 in Escherichia coli

Simian virus 40 mutant with transposed T-antigen and VP1 genes

Interaction of Simian Virus 40 chromatin with Simian Virus 40 T-antigen

Contact Info

Product

Resources

About