SN- and NS-puckered sugar conformers are precursors of the (6–4) photoproduct in thymine dinucleotide

Abstract

The S conformation of at least one sugar residue in the TT site is crucial for (6–4) PP formation. This S sugar can be located at the 5′- or 3′-end of the TT site. The 5′-end S conformer location is the most efficient at providing (6–4) PP.

Selective enhancement of (6–4) photoproduct formation in dithymine dinucleotides driven by specific sugar puckering

“…So far, the photochemistry of ten modified dinucleotides ( 2–11 ) has been reported with various degrees of precision. 14,18 Seven of those dinucleotides ( 5–11 , Fig. 3) contain the canonical phosphodiester linkage between modified sugar residues and the other three ( 2–4 , Fig.…”

“…Experimentally scrutinizing the relative formation of (6–4)/CPD at the dithymine dinucleotide DNA level, we previously reported that the ground-state conformation of sugar could dramatically drive (6–4) PP formation in a quantitative manner. 14 With this crucial and recently collected information in hand, we think it is now possible and timely to envision a search for candidates able to specifically increase the efficiency of (6–4) PP formation without affecting that of CPD. Such compounds would undoubtedly give access to the ground-state conformation of precursor species prone to oxetane formation.…”