title: Structure and function of the UvrB protein.
abstract: UvrB plays a central role in (A)BC excinuclease. To identify the regions of UvrB which are involved in interacting with UvrA, UvrC, and DNA, deletion mutants, point mutants, and various fusion forms of UvrB were constructed and characterized. We found that the region encompassing amino acid residues 115-250 of UvrB binds to UvrA, while the region encompassing amino acid residues 547-673 binds to both UvrA and UvrC. In addition, the region between these two domains, which contains the helicase motifs II-VI, was found to be involved in binding to DNA. Within this DNA-binding region, two point mutants, E265A and E338A, were found to be unable to bind DNA while two residues, Phe-365 and Phe-496, were identified to interact with DNA. Furthermore, fluorescence quenching studies with mutants F365W and F496W and repair of thymine cyclobutane dimers by photoinduced electron transfer by these mutants suggest that residues Phe-365 and Phe-496 interact with DNA most likely through stacking interactions.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Hsu
authors.forename: S T
authors.initials: ST
authors.lastname: Kim
authors.forename: Q
authors.initials: Q
authors.lastname: Sun
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003432:Cross-Linking Reagents / Q000737:chemistry; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000378:metabolism; D004706:Endodeoxyribonucleases; D029968:Escherichia coli Proteins; D005363:Ficusin / Q000737:chemistry; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D017354:Point Mutation; D011485:Protein Binding; D011740:Pyrimidine Dimers / Q000378:metabolism; D017384:Sequence Deletion; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D009838:Oligodeoxyribonucleotides; D011740:Pyrimidine Dimers; C058093:UvrB protein, E coli; D004247:DNA; D004706:Endodeoxyribonucleases; C066567:UvrC protein, E coli; C068631:UvrA protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D005363:Ficusin