Residue conformations ------------------------------------------- 1 : U C3p_endo anti 2 : G C3p_endo anti 3 : A C3p_endo anti 4 : U C3p_endo anti 5 : C C3p_endo anti 6 : G C3p_endo anti Adjacent stackings ---------------------------------------------- Non-Adjacent stackings ------------------------------------------ 2-6 : outward Number of stackings = 1 Number of adjacent stackings = 0 Number of non adjacent stackings = 1 Base-pairs ------------------------------------------------------ 1-6 : U-G Ws/Ww pairing antiparallel cis XXVIII 3-4 : A-U Ww/Ww pairing antiparallel cis XX