Sulfolobus chromatin proteins modulate strand displacement by DNA polymerase B1.

ABSTRACT: Strand displacement by a DNA polymerase serves a key role in Okazaki fragment maturation, which involves displacement of the RNA primer of the preexisting Okazaki fragment into a flap structure, and subsequent flap removal and fragment ligation. We investigated the role of Sulfolobus chromatin proteins Sso7d and Cren7 in strand displacement by DNA polymerase B1 (PolB1) from the hyperthermophilic archaeon Sulfolobus solfataricus. PolB1 showed a robust strand displacement activity and was capable of synthesizing thousands of nucleotides on a DNA-primed 72-nt single-stranded circular DNA template. This activity was inhibited by both Sso7d and Cren7, which limited the flap length to 3-4 nt at saturating concentrations. However, neither protein inhibited RNA displacement on an RNA-primed single

SUBMITTER: Sun F 

PROVIDER: S-EPMC3783171 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature