Cd. Roussev et al., External transesterification of ribonucleotide esters naturally catalyzed by large ribozymes, J AM CHEM S, 121(49), 1999, pp. 11267-11272
The intriguing chemical mechanism of the external transesterification by wh
ich large ribozymes (group I, group II, and spliceosomal introns) splice RN
A has been found to operate in the methanolysis of ribonucleoside 2'-/3'-di
methyl phosphates in non-hydrogen-bonding organic solvents. Besides needing
aprotic organic media this mechanism requires a high concentration of the
attacking alcohol accounting for the binding of an external guanosine by gr
oup I introns and the use of a non-adjacent internal 2'-OH by group II and
spliceosomal introns. This finding is the first example of an external non-
ribozymic transesterification of ribonucleotide esters and the means by whi
ch this crucial biochemical reaction can be accelerated.