# Solution structure of Z-form DNA bound to a curaxin ligand CBL0137

## TL;DR

This study reveals the first high-resolution structure of Z-DNA bound to a curaxin compound, offering insights for developing new cancer treatments.

## Contribution

The first high-resolution structure of Z-DNA bound to a curaxin ligand CBL0137 is presented.

## Key findings

- CBL0137 interacts with Z-DNA through π-stacking and zig-zag localization.
- The Z-DNA-CBL0137 complex was observed in living human cells using in-cell 19F NMR.
- The structure provides a foundation for designing Z-DNA-targeting anticancer drugs.

## Abstract

Z-DNA is known to be a left-handed alternative form of DNA and has important biological roles in cancer and other genetic diseases. In a recent study, we discovered CBL0137, a curaxin ligand, to enhance cancer immunotherapy by inducing Z-DNA formation and activating the Z-DNA-binding protein ZBP1. However, the structural information on binding complexes between Z-DNA and CBL0137 ligand has not reported to date. Here we present the first high-resolution structure of the complex between a Z-DNA and a curaxin ligand CBL0137. This compound is observed to interact with the Z-DNA through π-stacking and zig-zag localization. Furthermore, we directly observe the complex in living human cells using in-cell 19F NMR for the first time. This structural information provides a platform for the design of topology-specific Z-DNA-targeting compounds and is valuable for the development of new potent anticancer drugs.

Graphical Abstract