A DNA-topoisomerase-II-binding protein with eight repeating regions similar to DNA-repair enzymes and to a cell-cycle regulator

Eur J Biochem. 1997 Dec 15;250(3):794-9. doi: 10.1111/j.1432-1033.1997.00794.x.

Abstract

A two-hybrid system was used to isolate factors that interact with the C-terminal region of DNA topoisomerase IIbeta. A positive clone isolated from a HeLa cDNA library encoded 1522 amino acid residues (molecular mass 170670). The protein, designated topoisomerase-IIbeta-binding protein 1 (TopBP1), interacted with the C-terminal region of topoisomerase IIbeta synthesized in vitro. A database search indicated that TopBP1 possessed eight regions similar to regions of Rad4, Cut5, Ect2, Rev1 and X-ray repair cross-complementing 1 (XRCC1) proteins and a region similar to auto-modification sites of poly(ADP-ribose) polymerase, suggesting that TopBP1 supported catalytic reactions of topoisomerase II through transient breakages of DNA strands.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Northern
  • Carrier Proteins / chemistry*
  • Cloning, Molecular
  • DNA Ligases / chemistry*
  • DNA Ligases / metabolism
  • DNA Topoisomerases, Type II / metabolism*
  • DNA-Binding Proteins
  • Escherichia coli / genetics
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins
  • Protein Binding
  • RNA, Messenger / analysis
  • RNA, Messenger / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / isolation & purification
  • Saccharomyces cerevisiae / genetics
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid

Substances

  • Carrier Proteins
  • DNA-Binding Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • TOPBP1 protein, human
  • DNA Topoisomerases, Type II
  • DNA Ligases

Associated data

  • GENBANK/AB019397