Nucleic Acids Research, 2003, Vol. 31, No. 5 1536-1540
© 2003 Oxford University Press
The role of minor groove functional groups in DNA hydration
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA and 1 Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
*To whom correspondence should be addressed. Tel: +1 404 894 9752; Fax: +1 404 894 7452; Email: loren.williams{at}chemistry.gatech.edu
Here we describe the crystal structure of modified [d(CGCGAATTCGCG)]2 refined to 2.04 Å. The modification, which affects only the two thymines at the central ApT step, involves isosteric removal of the 2-keto oxygen atoms and substitution of the N1 nitrogen with carbon. The crystal structure reveals the ability of this modified thymine to effectively base pair with adenine in [d(CGCGAAtTCGCG)]2. The structure also suggests that the minor groove ‘spine of hydration’ is destabilized but essentially intact.