Nucleotide mimicry in the crystal structure of the uracil-DNA glycosylase-uracil glycosylase inhibitor protein complex

Nat Struct Biol. 1995 Sep;2(9):752-7. doi: 10.1038/nsb0995-752.


The Bacillus subtilis bacteriophages PBS-1 and PBS-2 protect their uracil-containing DNA by expressing an inhibitor protein (UGI) which inactivates the host uracil-DNA glycosylase (UDGase) base-excision repair enzyme. Also, PBS1/2 UGI efficiently inactivates UDGases from other biological sources, including the enzyme from herpes simplex virus type-1 (HSV-1). The crystal structure of the HSV-1 UDGase-PBS1 UGI complex at 2.7 angstrum reveals an alpha-beta-alpha sandwich structure for UGI which interacts with conserved regions of UDGase involved in DNA binding, and directly mimics protein-DNA interactions observed in the UDGase-oligonucleotide complex. The inhibitor completely blocks access to the active site of UDGase, but makes no direct contact with the uracil-binding pocket itself.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / chemistry
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Bacteriophages / chemistry
  • Crystallography, X-Ray
  • DNA Glycosylases*
  • Molecular Sequence Data
  • N-Glycosyl Hydrolases / antagonists & inhibitors*
  • N-Glycosyl Hydrolases / chemistry*
  • N-Glycosyl Hydrolases / metabolism
  • Nucleotides / chemistry
  • Nucleotides / metabolism
  • Protein Conformation
  • Simplexvirus / enzymology
  • Uracil-DNA Glycosidase
  • Viral Proteins / chemistry*
  • Viral Proteins / metabolism
  • Viral Proteins / pharmacology


  • Bacterial Proteins
  • Nucleotides
  • Viral Proteins
  • uracil-DNA glycosylase inhibitor protein, B. subtilis bacteriophage
  • DNA Glycosylases
  • N-Glycosyl Hydrolases
  • Uracil-DNA Glycosidase