The archaeal ATPase PINA interacts with the helicase Hjm via its carboxyl terminal KH domain remodeling and processing replication fork and Holliday junction

ABSTRACT: PINA is a novel ATPase and DNA helicase highly conserved in archaea, the third domain of life. The PINA from Sulfolobus islandicus (SisPINA) forms a hexameric ring, promotes Holliday junction (HJ) migration, and physically and functionally interacts with Hjc, the HJ specific endonuclease. Here, we show that SisPINA has strong physical interaction with Hjm (Hel308a), a helicase presumably targeting replication forks. In vitro biochemical analysis revealed that Hjm, Hjc, and SisPINA are able to coordinate HJ migration and cleavage in a concerted way. Deletion of the carboxyl 13 amino acid residues abolishes the interaction between SisPINA and Hjm. Crystal structure analysis showed that the carboxyl 70 amino acid residues fold into a type II KH domain which, in other proteins, functions in binding RNA and ssDNA. The KH domain not only mediates the interactions of PINA with Hjm and Hjc but also regulates the hexameric assembly of PINA. Our results collectively suggest possible mechanisms for SisPINA, Hjm, and Hjc to work together in replication fork regression, HJ formation, and HJ cleavage.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Sulfolobus Islandicus Rey15a

TISSUE(S): Whole Body

SUBMITTER: Rachel Green  

LAB HEAD: Yulong Shen

PROVIDER: PXD008644 | Pride | 2018-10-22

REPOSITORIES: Pride