The solution structure of [d(CGC)r(amamam)d(TTTGCG)]2

摘要: The solution structure and hydration of a DNA.RNA hybrid chimeric duplex [d(CGC)r(amamam)d(TTTGCG)]2 in which the RNA adenines were substituted by 2'-O-methylated riboadenines was determined using two-dimensional NMR, simulated annealing, restrained molecular dynamics. Only DNA residue 7T 2'-OMe-RNA.DNA junction adopted an O4'-endo sugar conformation, while other residues including 3C DNA.2'-OMe-RNA junction, C1'-exo or C2'-endo conformations. observed NOE intensity 2'-O-methyl group to H1' proton 4am at is much weaker than those 5am 6am. found orient towards minor groove trans domain groups 6am be gauche (+) domain. In contrast long-lived water molecules close adenine H2 protons methyl RNA-DNA [d(CGC)r(aaa)d(TTTGCG)]2, there no [d(CGC)r(amamam)d(TTTGCG)]2. This probably due hydrophobic enviroment created wider width middle structure. addition, 2'-O-methylation pure increses its melting temperature from 48.5 degrees C 51.9 C. characteristic structural features patterns this provide basis for further therapeutic applications duplexes with 2'-modified residues.