Evidence from extended X-ray absorption fine structure and site-specific mutagenesis for zinc fingers in UvrA protein of Escherichia coli

J Biol Chem. 1989 Sep 25;264(27):16067-71.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / genetics*
  • DNA-Binding Proteins / genetics*
  • Escherichia coli / genetics*
  • Fourier Analysis
  • Metalloproteins / genetics*
  • Mutation*
  • Protein Conformation
  • Sequence Homology, Nucleic Acid
  • Spectrum Analysis
  • Thermodynamics
  • X-Rays
  • Zinc*

Substances

  • Bacterial Proteins
  • DNA-Binding Proteins
  • Metalloproteins
  • Zinc