Abstract
We have synthesized and studied by proton NMR a duplex heptaoligonucleotide containing a 5-bromouracil (brU)-adenine base pair. This represents the first structural characterization of a B-form DNA containing brU. The brU.A base pair is Watson-Crick rather than Hoogsteen as seen for the monomers in the crystalline state. From analysis of the NOESY sepctra at very short mixing times evidence is presented that substitution of brU for T induces significant conformational changes from that of a normal B DNA. The helix twist between brU4.A11 and G3.C12 is ca. 15 degrees and for both brU4 and G3 the glycosyl torsion angles are significantly changed. The imino proton of the bru.A base pair shows a pH insensitive line with which shows that the pK of brU in this base pair is very much higher than that of the monomer.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
