Helicase promotes replication re-initiation from an RNA transcript. Academic Article uri icon

Overview

abstract

  • To ensure accurate DNA replication, a replisome must effectively overcome numerous obstacles on its DNA substrate. After encountering an obstacle, a progressing replisome often aborts DNA synthesis but continues to unwind. However, little is known about how DNA synthesis is resumed downstream of an obstacle. Here, we examine the consequences of a non-replicating replisome collision with a co-directional RNA polymerase (RNAP). Using single-molecule and ensemble methods, we find that T7 helicase interacts strongly with a non-replicating T7 DNA polymerase (DNAP) at a replication fork. As the helicase advances, the associated DNAP also moves forward. The presence of the DNAP increases both helicase's processivity and unwinding rate. We show that such a DNAP, together with its helicase, is indeed able to actively disrupt a stalled transcription elongation complex, and then initiates replication using the RNA transcript as a primer. These observations exhibit T7 helicase's novel role in replication re-initiation.

publication date

  • June 13, 2018

Research

keywords

  • DNA Helicases
  • DNA Replication

Identity

PubMed Central ID

  • PMC5997990

Scopus Document Identifier

  • 85048503712

Digital Object Identifier (DOI)

  • 10.1016/S0006-3495(03)74946-7

PubMed ID

  • 29899338

Additional Document Info

volume

  • 9

issue

  • 1