The influence of base pair tautomerism on single point mutations in aqueous DNA

© 2020 The Authors..

The relationship between base pair hydrogen bond proton transfer and the rate of spontaneous single point mutations at ambient temperatures and pressures in aqueous DNA is investigated. By using an ensemble-based multiscale computational modelling method, statistically robust rates of proton transfer for the A:T and G:C base pairs within a solvated DNA dodecamer are calculated. Several different proton transfer pathways are observed within the same base pair. It is shown that, in G:C, the double proton transfer tautomer is preferred, while the single proton transfer process is favoured in A:T. The reported range of rate coefficients for double proton transfer is consistent with recent experimental data. Notwithstanding the approximately 1000 times more common presence of single proton transfer products from A:T, observationally there is bias towards G:C to A:T mutations in a wide range of living organisms. We infer that the double proton transfer reactions between G:C base pairs have a negligible contribution towards this bias for the following reasons: (i) the maximum half-life of the G*:C* tautomer is in the range of picoseconds, which is significantly smaller than the milliseconds it takes for DNA to unwind during replication, (ii) statistically, the majority of G*:C* tautomers revert back to their canonical forms through a barrierless process, and (iii) the thermodynamic instability of the tautomers with respect to the canonical base pairs. Through similar reasoning, we also deduce that proton transfer in the A:T base pair does not contribute to single point mutations in DNA.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Interface focus - 10(2020), 6 vom: 06. Dez., Seite 20190120

Sprache:

Englisch

Beteiligte Personen:

Gheorghiu, A [VerfasserIn]
Coveney, P V [VerfasserIn]
Arabi, A A [VerfasserIn]

Links:

Volltext

Themen:

DNA mutation
High-performance computing
Journal Article
Multiscale modelling
Proton transfer

Anmerkungen:

Date Revised 24.09.2021

published: Print-Electronic

figshare: 10.6084/m9.figshare.c.5113667

Citation Status PubMed-not-MEDLINE

doi:

10.1098/rsfs.2019.0120

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM317459864