Origin binding by a 100,000-dalton super-T antigen from SVT2 cells.
The SVT2 line of simian virus 40-transformed mouse cells expresses little or no wild-type-size A protein (T antigen). Instead, a variant form is produced in these cells that is larger than normal-size A protein. This variant form has an Mr of 100,000 (100K super-T antigen) and is found primarily in complexes with the host-cell-coded p53 protein. Binding of the 100K super-T antigen to simian virus 40 origin region DNA was assayed by immunoprecipitation of super-T antigen-DNA complexes and then digestion with DNase I. DNA sequences associated with super-T antigen were protected from digestion and retained in the immune complex, while unprotected sequences were digested and released. The 100K super-T antigen efficiently protects DNA sequences in the previously defined regions I and II (P. Tegtmeyer, B. A. Lewton, A. L. DeLucia, V. G. Wilson, and K. Ryder, J. Virol. 46:151-161, 1983). Within region II (the origin of replication), the pattern and size of protected fragments are identical for super-T antigen and purified wild-type A protein. Thus, even though super-T antigen is larger than wild-type A protein, both must bind with the same alignment on origin DNA. Furthermore, complexes between the host-cell-coded p53 protein and the 100K super-T antigen also retain the ability to bind in regions I and II.
Wilson
V G
VG
Williams
R L
RL
D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D002472:Cell Transformation, Viral; D004279:DNA, Viral / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D046911:Macromolecular Substances; D008970:Molecular Weight; D011485:Protein Binding; D013539:Simian virus 40 / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*
D000952:Antigens, Polyomavirus Transforming; D000957:Antigens, Viral, Tumor; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D014764:Viral Proteins