Removal of a displaced Okazaki initiator RNA by FEN1/RTH1 nuclease. As synthesis of the upstream Okazaki fragment is completed, DNA polymerase with a DNA helicase displaces both RNA and DNA of the downstream fragment, generating an unannealed 5'-tail. FEN1/RTH1 binds and tracks over the 5-tail. Then, FEN1/RTH1 endonucleolytically cleaves the 5'-tail removing the entire RNA primer.
From: R. A. Bambara, R. S. Murante, and L. A. Henricksen (1997) Enzymes and reactions at the eukaryotic DNA replication fork. J. Biol. Chem. 272: 4647-4650.