title: Specific protein binding to the simian virus 40 enhancer in vitro.
abstract: HeLa cell nuclear extracts and wild-type or mutated simian virus 40 enhancer DNA were used in DNase I footprinting experiments to study the interaction of putative trans-acting factors with the multiple enhancer motifs. We show that these nuclear extracts contain proteins that bind to these motifs. Because point mutations which are detrimental to the activity of a particular enhancer motif in vivo specifically prevent protection of that motif against DNase I digestion in vivo, we suggest that the bound proteins correspond to trans-acting factors involved in enhancement of transcription. Using mutants in which the two domains A and B of the simian virus 40 enhancer are either separated by insertion of DNA fragments or inverted with respect to their natural orientation, we also demonstrate that the trans-acting factors bind independently to the two domains.
mesh_terms: D001483:Base Sequence; D002467:Cell Nucleus / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics*; D003850:Deoxyribonuclease I; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D013539:Simian virus 40 / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D003850:Deoxyribonuclease I