Structural Studies of Sv40 Large T-antigen on the Origin of Replication
نویسندگان
چکیده
Centro Nacional de Biotecnología, Campus Univ. Autónoma, 28049 Madrid, Spain, Health Research Inc., Howard Hughes Medical Institute at Wadsworth Center, Empire State Plaza, Albany, NY 12201-0509, and Department of Biomedical Sciences, State University of New York at Albany, University of Konstanz, Department of Biology, 78457 Konstanz, Germany, Max-Planck-Institut fur Biophysik, Frankfurt, Germany
منابع مشابه
Simian virus 40 (SV40) large tumor antigen causes stepwise changes in SV40 origin structure during initiation of DNA replication.
We have studied structural changes in the simian virus 40 (SV40) replication origin induced by SV40 large tumor antigen (T antigen). T-antigen-induced changes in origin DNA conformation can be visualized as specific and discrete topologic changes in origin DNA minicircles. We discovered three origin-T-antigen complexes defined by changes in DNA linking number. These complexes probably reflected...
متن کاملSimian virus 40 (SV40) DNA replication: SV40 large T antigen unwinds DNA containing the SV40 origin of replication.
The simian virus 40 (SV40) large T antigen (large tumor antigen), in conjunction with a topoisomerase, a DNA binding protein, and ATP, catalyzed the conversion of a circular duplex DNA molecule containing the SV40 origin of replication to a form with unusual electrophoretic mobility that we have named form U. Analysis of this molecule revealed it to be a highly underwound covalently closed circ...
متن کاملSimian virus 40 large T antigen untwists DNA at the origin of DNA replication.
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 sit...
متن کاملThe simian virus 40 T antigen double hexamer assembles around the DNA at the replication origin.
An initial step in the replication of simian virus (SV40) DNA is the ATP-dependent formation of a double hexamer of the SV40 large tumor (T) antigen at the SV40 DNA replication origin. In the absence of DNA, T antigen assembled into hexamers in the presence of magnesium and ATP. Hexameric T antigen was stable and could be isolated by glycerol gradient centrifugation. The ATPase activities of he...
متن کاملPhosphorylation of simian virus 40 T antigen on Thr 124 selectively promotes double-hexamer formation on subfragments of the viral core origin.
Cell cycle-dependent phosphorylation of simian virus 40 (SV40) large tumor antigen (T-ag) on threonine 124 is essential for the initiation of viral DNA replication. A T-ag molecule containing a Thr-->Ala substitution at this position (T124A) was previously shown to bind to the SV40 core origin but to be defective in DNA unwinding and initiation of DNA replication. However, exactly what step in ...
متن کاملThe Crystal Structure of the SV40 T-Antigen Origin Binding Domain in Complex with DNA
DNA replication is initiated upon binding of "initiators" to origins of replication. In simian virus 40 (SV40), the core origin contains four pentanucleotide binding sites organized as pairs of inverted repeats. Here we describe the crystal structures of the origin binding domain (obd) of the SV40 large T-antigen (T-ag) both with and without a subfragment of origin-containing DNA. In the co-str...
متن کامل