STN1-POLA2 interaction provides a basis for primase-pol α stimulation by human STN1.

ABSTRACT: The CST (CTC1-STN1-TEN1) complex mediates critical functions in maintaining telomere DNA and overcoming genome-wide replication stress. A conserved biochemical function of the CST complex is its primase-Pol α (PP) stimulatory activity. In this report, we demonstrate the ability of purified human STN1 alone to promote PP activity in vitro. We show that this regulation is mediated primarily by the N-terminal OB fold of STN1, but does not require the DNA-binding activity of this domain. Rather, we observed a strong correlation between the PP-stimulatory activity of STN1 variants and their abilities to bind POLA2. Remarkably, the main binding target of STN1 in POLA2 is the latter's central OB fold domain. In the substrate-free structure of PP, this domain is positioned so as to block nucleic a

SUBMITTER: Ganduri S 

PROVIDER: S-EPMC5766158 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature