Figure 9.

A model for the role of Sulfolobus chromatin proteins in Okazaki fragment maturation. Chromatin proteins, bound to double-stranded regions during lagging strand synthesis (A), become disassociated from the RNA:DNA hybrid region when PolB1 displaces the RNA primer (B). The displaced strand undergoes multiple rounds of flap cleavage by Fen1. PolB1 stops strand displacement on entering the dsDNA region, which is stably bound by the chromatin proteins (C). The resulting nick was sealed by DNA ligase as the newly synthesized Okazaki fragment was ligated into the lagging strand (D). PCNA, Fen1 and DNA ligase are omitted.