The Transmission of the Electronic Character of Guanin-9-yl Drives the Sugar-Phosphate Backbone Torsions in Guanosine 3',5'-Bisphosphate.
The intrinsic flexibility of the pentoses in RNA allows dynamic transmission of information on the electronic character of the nucleobase to modulate the sugar conformation by an interplay of gauche and anomeric effects. This modulation in turn steers the phosphate backbone conformation by tuning the 3'-O-P-O(ester) anomeric effect, as shown by conformational analysis of EtpGpMe as a function of pD. This tunable transmission is stereoelectronic in nature, and operates by appropriate overlap between donor and acceptor orbitals (see scheme), which causes single-stranded RNA to behave as a molecular wire.
Acharya
P
Department of Bioorganic Chemistry, Box 581, Biomedical Centre, University of Uppsala, S-751 23 Uppsala (Sweden).
Trifonova
A
Thibaudeau
C
Földesi
A
Chattopadhyaya
J