Nanopore Sequencing Accurately Identifies the Mutagenic DNA Lesion O6 -Carboxymethyl Guanine and Reveals Its Behavior in Replication

Angew Chem Int Ed Engl. 2019 Jun 17;58(25):8432-8436. doi: 10.1002/anie.201902521. Epub 2019 May 13.

Abstract

O6 -carboxymethylguanine (O6 -CMG) is a highly mutagenic alkylation product of DNA, triggering transition mutations relevant to gastrointestinal cancer. However, precise localization of a single O6 -CMG with conventional sequencing platforms is challenging. Here nanopore sequencing (NPS), which directly senses single DNA bases according to their physiochemical properties, was employed to detect O6 -CMG. A unique O6 -CMG signal was observed during NPS and a single-event call accuracy of >95 % was achieved. Moreover, O6 -CMG was found to be a replication obstacle for Phi29 DNA polymerase (Phi29 DNAP), suggesting this lesion could cause DNA sequencing biases in next generation sequencing (NGS) approaches.

Keywords: DNA lesion; carboxymethyl guanine; gastrointestinal cancer; nanopore sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA / chemistry
  • DNA / genetics*
  • DNA-Directed DNA Polymerase / genetics*
  • DNA-Directed DNA Polymerase / metabolism
  • Guanine / analogs & derivatives
  • Guanine / chemistry*
  • Humans
  • Molecular Structure
  • Nanopore Sequencing

Substances

  • Guanine
  • DNA
  • DNA-Directed DNA Polymerase