This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Scheller, A Articles by Prives, C Search for Related Content PubMed PubMed Citation Articles by Scheller, A Articles by Prives, C

 Previous Article  |  Next Article 

J Virol. 1985 May; 54(2): 532-545

Simian virus 40 and polyomavirus large tumor antigens have different requirements for high-affinity sequence-specific DNA binding.

ABSTRACT

By using a DNA fragment immunoassay, the binding of simian virus 40 (SV40) and polyomavirus (Py) large tumor (T) antigens to regulatory regions at both viral origins of replication was examined. Although both Py T antigen and SV40 T antigen bind to multiple discrete regions on their proper origins and the reciprocal origin, several striking differences were observed. Py T antigen bound efficiently to three regions on Py DNA centered around an MboII site at nucleotide 45 (region A), a BglI site at nucleotide 92 (region B), and another MboII site at nucleotide 132 (region C). Region A is adjacent to the viral replication origin, and region C coincides with the major early mRNA cap site. Weak binding by Py T antigen to the origin palindrome centered at nucleotide 3 also was observed. SV40 T antigen binds strongly to Py regions A and B but only weakly to region C. This weak binding on region C was surprising because this region contains four tandem repeats of GPuGGC, the canonical pentanucleotide sequence thought to be involved in specific binding by T antigens. On SV40 DNA, SV40 T antigen displayed its characteristic hierarchy of affinities, binding most efficiently to site 1 and less efficiently to site 2. Binding to site 3 was undetectable under these conditions. In contrast, Py T antigen, despite an overall relative reduction of affinity for SV40 DNA, binds equally to fragments containing each of the three SV40 binding sites. Py T antigen, but not SV40 T antigen, also bound specifically to a region of human Alu DNA which bears a remarkable homology to SV40 site 1. However, both tumor antigens fail to precipitate DNA from the same region which has two direct repeats of GAGGC. These results indicate that despite similarities in protein structure and DNA sequence, requirements of the two T antigens for pentanucleotide configuration and neighboring sequence environment are different.

This article has been cited by other articles:

• Love, T. M., de Jesus, R., Kean, J. A., Sheng, Q., Leger, A., Schaffhausen, B. (2005). Activation of CREB/ATF Sites by Polyomavirus Large T Antigen. J. Virol. 79: 4180-4190 [Abstract] [Full Text]  
• Peng, Y.-C., Acheson, N. H. (1998). Polyomavirus Large T Antigen Binds Cooperatively to Its Multiple Binding Sites in the Viral Origin of DNA Replication. J. Virol. 72: 7330-7340 [Abstract] [Full Text]