Related Experiment Video

Updated: Sep 13, 2026

Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage
10:44

Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage

Published on: January 31, 2018

Physical and functional interaction between DNA ligase IIIalpha and poly(ADP-Ribose) polymerase 1 in DNA

John B Leppard1, Zhiwan Dong, Zachary B Mackey

  • 1Department of Molecular Medicine, Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245, USA.

Molecular and Cellular Biology
|August 5, 2003
PubMed

Insights

Poly(ADP-ribose) polymerase 1 (PARP-1) and DNA ligase IIIalpha are crucial for DNA repair. This study reveals how PARP-1 recruits DNA ligase IIIalpha to DNA breaks, ensuring genome stability.

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • DNA single-strand breaks are repaired by PARP-1, DNA ligase IIIalpha, and XRCC1 in mammals.
  • This pathway is unique to complex organisms and vital for genome stability.
  • XRCC1 forms complexes with DNA ligase IIIalpha and other repair factors.

Purpose of the Study:

  • To identify proteins interacting with DNA ligase III.
  • To elucidate the mechanism of DNA ligase IIIalpha recruitment to DNA breaks.

Main Methods:

  • Affinity chromatography to identify protein interactions.
  • Biochemical assays to study protein-DNA and protein-polymer binding.
  • In vitro and in vivo association studies.

Main Results:

  • PARP-1 directly binds to the N-terminal region of DNA ligase III, near its zinc finger.
  • DNA ligase III binds poly(ADP-ribose) and associates with poly(ADP-ribosyl)ated PARP-1.
  • The DNA ligase III zinc finger enhances DNA joining in the presence of poly(ADP-ribosyl)ated PARP-1 or poly(ADP-ribose).

Conclusions:

  • A mechanism for recruiting the DNA ligase IIIalpha-XRCC1 complex to DNA breaks is proposed.
  • The DNA ligase III zinc finger facilitates the complex's localization to strand breaks via poly(ADP-ribose).
  • This interaction is essential for maintaining genome stability in complex organisms.

More Related Videos

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis11:08

Proofreading and DNA Repair Assay Using Single Nucleotide Extension and MALDI-TOF Mass Spectrometry Analysis

Published on: June 19, 2018

Visualization of DNA Repair Proteins Interaction by Immunofluorescence07:55

Visualization of DNA Repair Proteins Interaction by Immunofluorescence

Published on: June 26, 2020

Related Concept Videos

Long-patch Base Excision Repair01:02

Long-patch Base Excision Repair

Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
Translesion DNA Polymerases02:10

Translesion DNA Polymerases

Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
Fixing Double-strand Breaks02:04

Fixing Double-strand Breaks

The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Fixing Double-strand Breaks02:04

Fixing Double-strand Breaks

The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...