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RecA protein promotes the regression of stalled replication forks in vitro

M E Robu1, R B Inman, M M Cox

  • 1Department of Biochemistry, University of Wisconsin, Madison, WI 53706-1544, USA.

Proceedings of the National Academy of Sciences of the United States of America
|July 19, 2001
PubMed

Insights

Escherichia coli RecA protein promotes DNA replication fork regression in vitro, a crucial step in repairing stalled forks. This process requires ATP hydrolysis and aids in preventing double-strand breaks during DNA repair.

Area of Science:

  • Molecular Biology
  • DNA Replication and Repair
  • Biochemistry

Background:

  • DNA replication forks can stall when encountering DNA lesions.
  • Stalled forks may lead to single-strand gaps, potentially causing double-strand breaks.
  • Fork regression is a proposed mechanism to repair stalled forks without generating double-strand breaks.

Purpose of the Study:

  • To investigate the role of Escherichia coli RecA protein in promoting replication fork regression in vitro.
  • To elucidate the biochemical requirements for RecA-mediated fork regression.

Main Methods:

  • Utilized model DNA substrates mimicking stalled replication forks.
  • Assayed RecA protein-dependent fork regression in vitro.
  • Investigated the requirement for ATP hydrolysis and the effect of dATP.

Main Results:

  • RecA protein actively promotes DNA fork regression in vitro.
  • The regression reaction absolutely requires ATP hydrolysis.
  • dATP enhances the reaction compared to ATP.
  • RecO and RecR proteins do not affect the observed RecA-mediated regression.

Conclusions:

  • RecA protein plays a significant role in the fork regression reaction.
  • This reaction is essential for repairing stalled and/or collapsed replication forks in bacteria.
  • RecA-mediated fork regression is a key pathway for maintaining genome stability.

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