Title
Substrate-Dependent Conformational Landscape of Human DNA
Ligases (Research)
Abstract
DNA ligases catalyze the formation of phosphodiesters on the DNA
backbone and are therefore essential enzymes for DNA metabolism,
such as during replication and repair. Previous research resolved the
conserved modular core structure of DNA ligases and implicated that
large conformational changes take place during the catalytic cycle of
DNA ligases. However, it is unknown how protein flexibility regulates
the enzymatic turn-over rate and their ability to engage a set of
substrate structures. In this project, I will test the hypothesis that
structural dynamics of DNA ligases governs substrate selectivity and
enzyme turn-over rate using single-molecule FRET (smFRET) and
DNA origami-tethered substrates. Fluorescently-labeled substrate
DNA is used to investigate the dynamics of strand break probing by
all human DNA ligases. Strategically labeled human DNA ligase III
protein will subsequently be used as a model to capture the
conformational landscape of DNA ligases. This project will elucidate
the relationship between structural dynamics of human DNA ligases
and their enzymatic activity in order to understand their functioning in
different cellular contexts. In addition to fundamental insights, the
gained knowledge on conformational states of DNA ligases may
facilitate the understanding of disease mechanisms and the
development of specific inhibitors for targeted cancer therapy.
Period of project
01 November 2021 - 31 October 2023