Single Amino Acid Mutation Controls Hole Transfer Dynamics in DNA-Methyltransferase HhaI Complexes
Different mutagenic effects are generated by DNA oxidation that implies the formation of radical cation states (so-called holes) on purine nucleobases. The interaction of DNA with proteins may protect DNA from oxidative damage owing to hole transfer (HT) from the stack to aromatic amino acids. Howev...
| Authors: | , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2015 |
| Country: | España |
| Institution: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repository: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/175944 |
| Online Access: | https://hdl.handle.net/2445/175944 |
| Access Level: | Open access |
| Keyword: | Transferència d'energia Transferència de càrrega ADN Reparació de l'ADN Complexitat computacional Energy transfer Charge transfer DNA DNA repair Computational complexity |
| Summary: | Different mutagenic effects are generated by DNA oxidation that implies the formation of radical cation states (so-called holes) on purine nucleobases. The interaction of DNA with proteins may protect DNA from oxidative damage owing to hole transfer (HT) from the stack to aromatic amino acids. However, how protein binding affects HT dynamics in DNA is still poorly understood. Here, we report a computational study of HT in DNA complexes with methyltransferase HhaI with the aim of elucidating the molecular factors that explain why long-range DNA HT is inhibited when the glutamine residue inserted in the double helix is mutated into a tryptophan. We combine molecular dynamics, quantum chemistry, and kinetic Monte Carlo simulations and find that protein binding stabilizes the energies of the guanine radical cation states and significantly impacts the corresponding electronic couplings, thus determining the observed behavior, whereas the formation of a tryptophan radical leads to less efficient HT. |
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