title: Psoralen photofootprinting of protein-binding sites on DNA.
abstract: Using a BAL31 exonuclease assay to determine the sites of 4,5',8-trimethylpsoralen photocrosslinking in DNA we have shown that 5'-TA sites which are accessible to psoralen DNA interstrand photocrosslinking in naked DNA become inaccessible when protein, in casu, lambda-repressor E. coli or RNA polymerase are bound at their recognition DNA sequences (OR1 operator or deo1 promoter, respectively). These results show that psoralens can be used as photofootprinting reagents to study specific protein-DNA interactions.
authors.affiliation: Department of Biochemistry B, Panum Institute, University of Copenhagen, Denmark.
authors.forename: W P
authors.initials: WP
authors.lastname: Zhen
authors.forename: C
authors.initials: C
authors.lastname: Jeppesen
authors.forename: P E
authors.initials: PE
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005363:Ficusin / Q000378:metabolism*; D011564:Furocoumarins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010777:Photochemistry; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism; D014307:Trioxsalen / Q000378:metabolism; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D004268:DNA-Binding Proteins; D011564:Furocoumarins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D004247:DNA; D012321:DNA-Directed RNA Polymerases; D005363:Ficusin; D014307:Trioxsalen