Induced-Fit Recognition of CCG Trinucleotide Repeats by a Nickel-Chromomycin Complex Resulting in Large-Scale DNA Deformation
Tseng, W.H., Chang, C.K., Wu, P.C., Hu, N.J., Lee, G.H., Tzeng, C.C., Neidle, S., Hou, M.H.(2017) Angew Chem Int Ed Engl 56: 8761-8765
- PubMed: 28544401
- DOI: https://doi.org/10.1002/anie.201703989
- Primary Citation of Related Structures:
5XEW - PubMed Abstract:
Small-molecule compounds targeting trinucleotide repeats in DNA have considerable potential as therapeutic or diagnostic agents against many neurological diseases. Ni II (Chro) 2 (Chro=chromomycin A3) binds specifically to the minor groove of (CCG) n repeats in duplex DNA, with unique fluorescence features that may serve as a probe for disease detection. Crystallographic studies revealed that the specificity originates from the large-scale spatial rearrangement of the DNA structure, including extrusion of consecutive bases and backbone distortions, with a sharp bending of the duplex accompanied by conformational changes in the Ni II chelate itself. The DNA deformation of CCG repeats upon binding forms a GGCC tetranucleotide tract, which is recognized by Ni II (Chro) 2 . The extruded cytosine and last guanine nucleotides form water-mediated hydrogen bonds, which aid in ligand recognition. The recognition can be accounted for by the classic induced-fit paradigm.
Organizational Affiliation:
Institute of Genomics and Bioinformatics, National Chung Hsing University, 250 Kuo-kuang Rd., Taichung, Taiwan.