Stalled fork rescue

Stalled DNA replication forks can result in disastrous consequences for a cell if left unrepaired.  One way to rescue an unbroken, stalled DNA replication fork is by regression. Here the fork is moved in a backward direction away from the impediment so that repair can be facilitated. This reaction is known as fork regression and is catalyzed by a monomeric DNA helicase called RecG.  During this reaction, RecG extrudes a chicken-foot intermediate or Holliday Junction, the central intermediate of fork rescue pathways (and of homologous recombination). This junction can be further processed by either the RuvAB branch migration complex or the resolvase, RuvC.  Additional studies to understand fork rescue will be done at the single molecule level and will focus on the role of SSB in directing activities at stalled replication forks and the mechanism of action of several DNA helicases including RecG and RuvAB.