CST complex helps copy the second DNA strand during break-induced replication

Second-strand synthesis during break-induced DNA replication is impaired in yeast lacking the CST complex.

• Early steps of break-induced DNA replication, including 5' strand resection and D-loop formation, occur normally in yeast without the CST complex.
• CST is implicated in the critical step of second-strand synthesis in break-induced DNA replication.
• The role of CST in promoting second-strand synthesis is conserved in human cells.
• CST enhances the activity of DNA polymerase α-primase during second-strand synthesis.
• Break-induced DNA replication may support long-tract DNA synthesis independently of the S-phase replisome.

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