DSSR-PyMOL cartoon-block schematics: PDB entry 9mm8

PDB-id

9mm8; DSSR-derived features in text and JSON formats

Class

DNA

Method

X-ray (4.61 Å)

Summary

[t:ag+-hg2+:t--(ph8-ph9.5; 16s)] metal-mediated DNA base pair in tensegrity triangle grown at ph 8 and soaked in ph 9.5 for 16s

Reference

De A, Lu B, Ohayon YP, Woloszyn K, Livernois W, Perren L, Yang CF, Mao C, Botana AS, Hihath J, Canary JW, Sha R, Anantram MP, Vecchioni S (2025): "Transmetalation for DNA-Based Molecular Electronics." Small, 21, e2411518. doi: 10.1002/smll.202411518.

Abstract

The rational design of molecular electronics remains a grand challenge of materials science. DNA nanotechnology has offered unmatched control over molecular geometry, but direct electronic functionalization is a challenge. Here a generalized method is presented for tuning the local band structure of DNA using transmetalation in metal-mediated base pairs (mmDNA). A method is developed for time-resolved X-ray diffraction using self-assembling DNA crystals to establish the exchange of Ag₊ and Hg₂₊ in T:T base pairs driven by pH exchange. Transmetalation is tracked over six reaction phases as crystal pH is changed from pH 8.0 to 11.0, and vice versa. A detailed computational analysis of the electronic configuration and transmission in the ensuing crystal structures is then performed. This findings reveal a high conductance contrast in the lowest unoccupied molecular orbitals (LUMO) as a result of metalation. The ability to exchange single transition metal ions as a result of environmental stimuli heralds a means of modulating the conductance of DNA-based molecular electronics. In this way, both theoretical and experimental basis are established by which mmDNA can be leveraged to build rewritable memory devices and nanoelectronics.