Hydrogen bond formation between the naturally modified nucleobase and phosphate backbone.

ABSTRACT: Natural RNAs, especially tRNAs, are extensively modified to tailor structure and function diversities. Uracil is the most modified nucleobase among all natural nucleobases. Interestingly, >76% of uracil modifications are located on its 5-position. We have investigated the natural 5-methoxy (5-O-CH(3)) modification of uracil in the context of A-form oligonucleotide duplex. Our X-ray crystal structure indicates first a H-bond formation between the uracil 5-O-CH(3) and its 5'-phosphate. This novel H-bond is not observed when the oxygen of 5-O-CH(3) is replaced with a larger atom (selenium or sulfur). The 5-O-CH(3) modification does not cause significant structure and stability alterations. Moreover, our computational study is consistent with the experimental observation. The investigation on

SUBMITTER: Sheng J 

PROVIDER: S-EPMC3439885 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature