title: Evidence from extended X-ray absorption fine structure and site-specific mutagenesis for zinc fingers in UvrA protein of Escherichia coli.
abstract: The UvrA protein is the damage recognition subunit of the Escherichia coli repair enzyme ABC excision nuclease. Sequence analysis of this 940-amino acid protein revealed two regions of sequence homology to the zinc finger motif found in many DNA binding proteins. Physical and chemical analyses indicate about 2 zinc atoms/molecule. We have used extended x-ray absorption fine structure analysis to demonstrate that each of these zinc atoms is coordinated with 4 cysteine residues at a distance of 2.32 +/- 0.2 A. Substitution of one of the cysteines by a histidine, a serine, or an alanine in one of the potential finger sites resulted in a respective decrease in complementing activity. We thus conclude that the two zinc fingers identified by sequence analysis do indeed have zinc finger structure in UvrA protein.
authors.affiliation: Research Division, North East Wales Institute, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Navaratnam
authors.forename: G M
authors.initials: GM
authors.lastname: Myles
authors.forename: R W
authors.initials: RW
authors.lastname: Strange
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005583:Fourier Analysis; D008667:Metalloproteins / Q000235:genetics*; D009154:Mutation; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D013057:Spectrum Analysis; D013816:Thermodynamics; D014965:X-Rays; D015032:Zinc
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008667:Metalloproteins; D015032:Zinc