X.CHEN,J.A.MCDOWELL,R.KIERZEK,T.R.KRUGH,D.H.TURNER. NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND MOLECULAR MODELING REVEAL THAT DIFFERENT HYDROGEN BONDING PATTERNS ARE POSSIBLE FOR G.U PAIRS: ONE HYDROGEN BOND FOR EACH G.U PAIR IN R(GGCGUGCC)(2) AND TWO FOR EACH G.U PAIR IN R(GAGUGCUC)(2).. BIOCHEMISTRY V. 39 8970 2000 ASTM BICHAW US ISSN 0006-2960