X-ray crystallography and NMR show that 5-formylcytosine does not change the global structure of DNA

Jack S Hardwick (1) , Denis Ptchelkine (1) , Afaf H El-Sagheer (1) , Ian Tear (2) , Daniel Singleton (2) , Simon E V Phillips (3, 1) , Andrew N Lane (4) , Tom Brown (1)

1 University of Oxford
2 University of Southampton
3 Research Complex at Harwell
4 University of Kentucky, USA

The mechanism by which 5-formylcytosine (fC) is recognised by enzymes involved in epigenetic modification and reading of DNA is not known, and recently an unusual DNA structure (F-DNA) was proposed as the basis for enzyme recognition of clusters of fC. We used NMR and X-ray crystallography to compare several modified DNA duplexes with the unmodified analogues and show that in the crystal state they all belong to the A-family, but in solution they are all members of the B-family. Contrary to the previous study, we find that 5-formylcytosine does not significantly affect the structure of DNA, though there are modest local differences at the modification sites. Hence, global conformation changes are unlikely to account for the recognition *

Domaines: Sciences du Vivant [q-bio]; Chimie

Jack S Hardwick, Denis Ptchelkine, Afaf H El-Sagheer, Ian Tear, Daniel Singleton, et al.. X-ray crystallography and NMR show that 5-formylcytosine does not change the global structure of DNA. Nature Structural and Molecular Biology, 2017, 24, pp.544 - 552. ⟨10.1038/nsmb.3411⟩. ⟨hal-04019935⟩