Dimerization of double-stranded RNA possessing a 3'-overhanging single-stranded end.
A simple system derived from the acceptor stem of tRNA(Ala) is presented which undergoes a pH-dependent dimerization. This is brought about by formation of C+-G-C base triples of the pyrimidine motif type between protonated cytidines of the 3' single-stranded end and regularly paired G-C pairs in the double-helical stem. In addition, an unusual interaction between a protonated adenine and a regular G-C pair is suggested. The equilibrium between monomer and dimer forms can be monitored via NMR spectroscopy and UV melting curve analysis. A dimerization enthalpy of 159 kJ mol(-1) was found at pH 5.0. The system could serve as a model for inter- and intra-molecular association, respectively, of single-stranded and double-helical regions to enable optimal packing of large RNA molecules.
Vogtherr
M
M
Max-Planck-Institut für Molekulare Genetik, Berlin-Dahlem, Germany.
Kirchner
R
R
Zuleeg
T
T
Limmer
S
S
D019281:Dimerization; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D012330:RNA, Double-Stranded / Q000737:chemistry* / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
D012330:RNA, Double-Stranded