# Mechanisms of Damaged DNA Replication in Eukaryotes

> **NIH NIH R01** · UNIVERSITY OF IOWA · 2021 · $332,884

## Abstract

Project Summary/Abstract
Mutations play a fundamental role in the etiology of many diseases including cancers, diabetes,
epilepsy, schizophrenia, and others. Many of these mutations result from translesion synthesis,
a pathway the cell uses to bypass DNA damage during DNA replication. In translesion
synthesis, the high-fidelity classical DNA polymerase (i.e., the one involved in normal DNA
replication) encounters DNA damage and stalls. Low-fidelity non-classical polymerases are
recruited to the stalled replication fork where they carry out replication of the damaged DNA.
Each non-classical polymerase is specialized for incorporating nucleotides opposite a few types
of DNA damage. When the proper non-classical polymerase is used, damage bypass is not
mutagenic. When an improper one is used, it is mutagenic. The overall goal of the proposed
research is to understand the factors that affect the accuracy and efficiency of translesion
synthesis. We are particularly interested in examining how non-classical polymerases are
selected and regulated during translesion synthesis. Little is known about non-classical
polymerase selection and regulation, because these polymerases function within dynamic,
multi-protein complexes (bypass complexes) that are difficult to study. We are using an
innovative and novel combination of biochemical, biophysical, and structural approaches that
will allow us to overcome these challenges. In Aim 1, we will examine the architecture of bypass
complexes using single-molecule total internal reflection fluorescence (TIRF) experiments. In
Aim 2, we will examine the regulation of bypass complexes using steady state and pre-steady
state kinetics studies. In Aim 3, we will examine the structure of bypass complexes using X-ray
crystallography, small-angle X-ray scattering (SAXS) and Brownian dynamics (BD) simulations.

## Key facts

- **NIH application ID:** 10254427
- **Project number:** 5R01GM081433-13
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** M. TODD WASHINGTON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $332,884
- **Award type:** 5
- **Project period:** 2008-07-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10254427

## Citation

> US National Institutes of Health, RePORTER application 10254427, Mechanisms of Damaged DNA Replication in Eukaryotes (5R01GM081433-13). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10254427. Licensed CC0.

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