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Simian virus 40 large T antigen untwists DNA at the origin of DNA replication


, : Simian virus 40 large T antigen untwists DNA at the origin of DNA replication. Journal of Biological Chemistry 266(8): 5062-5071

Simian virus 40 large tumor antigen (SV40 T antigen) untwists DNA at the SV40 replication origin. In the presence of ATP, T antigen shifted the average linking number of an SV40 origin-containing plasmid topoisomer distribution. The loss of up to two helical turns was detected. The reaction required the presence of the 64-base pair core origin of replication containing T antigen DNA binding site II; binding site I had no effect on the untwisting reaction. The presence of human single-stranded DNA binding protein (SSB) slightly reduced the degree of untwisting in the presence of ATP. ATP hydrolysis was not required since untwisting occurred in the presence of nonhydrolyzable analogs of ATP. However, in the presence of a nonhydrolyzable analog of ATP, the requirement for the SV40 origin sequence was lost. The origin requirement for DNA untwisting was also lost in the absence of dithiothreitol. The origin-specific untwisting activity of T antigen is distinct from its DNA helicase activity, since helicase activity does not require the SV40 origin but does require ATP hydrolysis. The lack of a requirement for SSB or ATP hydrolysis and the reduction in the pitch of the DNA helix by just a few turns at the replication origin distinguishes this reaction from the T antigen-mediated DNA unwinding reaction, which results in the formation of a highly underwound DNA molecule. Untwisting occurred without a lag after the start of the reaction, whereas unwound DNA was first detected after a lag of 10 min. It is proposed that the formation of a multimeric T antigen complex containing untwisted DNA at the SV40 origin is a prerequisite for the initiation of DNA unwinding and replication.

US$29.90

PMID: 1848235


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Marengo, E.; Robotti, E.; Liparota, M.C.; Gennaro, M.C., 2003: A method for monitoring the surface conservation of wooden objects by Raman spectroscopy and multivariate control charts. The principles of quality control and multivariate statistical analysis were applied to the monitoring of the conservation state of wooden works of art. Three degradation processes (exposure to a wet atmosphere, to an acidic attack, and to UV ligh...

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Boudier, B., 1982: Herbicides that can be used in 1982 for opening up forests. Phytoma (339) 26-29

D.L.ddo, R.; Grandi, C.; Venturini, M.; Dalzoppo, D.; Negro, A.; Conconi, M.T.; Parnigotto, P.P., 2011: Recombinant human TAT-OP1 to enhance NGF neurogenic potential: preliminary studies on PC12 cells. Osteogenic protein 1 (OP1), also known as bone morphogenic protein-7 (BMP7), is a multifunctional cytokine with demonstrated neurogenic potential. As the recombinant OP1 (rhOP1) was shown to provide axonal guidance cues and to prevent the reductio...

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Lau, S.C., 1966: Separation and measurement of 3-hvdroxy-n, n-dimethyl-cis-crotonamide dimethyl phosphate and 3-hvdroxv-N-methyl-cis-crotonamide dimethyl phosphate residues in crops by selective cleanup procedures. Techniques are described for the selective determination of 2 phosphate insecticides: 3-hydroxy-N, N-dimethyl-cis-crotonamide dimethyl phosphate (Bidrin) and its N-monomethyl analog (Azodrin). The analysis is carried out in 2 steps: a separation p...