Hydroxylation of methylated CpG dinucleotides reverses stabilisation of DNA duplexes by cytosine 5-methylation

A. Thalhammer, A. S. Hansen, A. H. El-Sagheer, T. Brown and C. J. Schofield. Chem. Commun. 47, 5325-5327, 2011.


Cytosine-5-methylation stabilises DNA duplexes and is associated with transcriptional repression; 5-methylcytosine undergoes hydroxylation to 5-hydroxymethylcytosine, a modification of unknown biological function. Spectroscopic and calorimetric analyses show that 5-hydroxymethylcytosine introduction reverses the stabilising effect of 5-methylcytosine, suggesting that in some contexts, 5-methylcytosine hydroxylation may, along with other factors, contribute to the alleviation of transcriptional repression.