Residues located in the primase domain of the bacteriophage T7 primase-helicase are essential for loading the hexameric complex onto DNA.

ABSTRACT: The T7 primase-helicase plays a pivotal role in the replication of T7 DNA. Using affinity isolation of peptide-nucleic acid crosslinks and mass spectrometry, we identify protein regions in the primase-helicase and T7 DNA polymerase that form contacts with the RNA primer and DNA template. The contacts between nucleic acids and the primase domain of the primase-helicase are centered in the RNA polymerase subdomain of the primase domain, in a cleft between the N-terminal subdomain and the topoisomerase-primase fold. We demonstrate that residues along a beta sheet in the N-terminal subdomain that contacts the RNA primer are essential for phage growth and primase activity in vitro. Surprisingly, we found mutations in the primase domain that had a dramatic effect on the helicase. Substitution of

SUBMITTER: Hernandez AJ 

PROVIDER: S-EPMC9198812 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature