title: Solution structure of the origin DNA-binding domain of SV40 T-antigen.
abstract: The structure of the domain from simian virus 40 (SV40) large T-antigen that binds to the SV40 origin of DNA replication (T-ag-OBD131-260) has been determined by nuclear magnetic resonance spectroscopy. The overall fold, consisting of a central five-stranded antiparallel beta-sheet flanked by two alpha-helices on one side and one alpha-helix and one 3(10)-helix on the other, is a new one. Previous mutational analyses have identified two elements, termed A (approximately 152-155) and B2 (203-207), as essential for origin-specific recognition. These elements form two closely juxtaposed loops that define a continuous surface on the protein. The addition of a duplex oligonucleotide containing the origin recognition pentanucleotide GAGGC induces chemical shift changes and slows amide proton exchange in resonances from this region, indicating that this surface directly contacts the DNA.
authors.affiliation: Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
authors.forename: X
authors.initials: X
authors.lastname: Luo
authors.forename: D G
authors.initials: DG
authors.lastname: Sanford
authors.forename: P A
authors.initials: PA
authors.lastname: Bullock
authors.forename: W W
authors.initials: WW
authors.lastname: Bachovchin
mesh_terms: D000595:Amino Acid Sequence; D000952:Antigens, Polyomavirus Transforming / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013539:Simian virus 40 / Q000276:immunology*
chemical_list: D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral