Selection of hammerhead ribozyme variants with low Mg2+ requirement: Importance of stem-loop II
Variants of the hammerhead ribozyme with high in trans (intermolecular) cleavage activity at low Mg2- concentrations were in vitro selected from a library with 78 nucleotides randomised in the core and in helix II. The most active hammerhead ribozyme selected had e sequence as the consensus ribozyme in the core but only two base pairs in stem II, G(10.1)-C(11.1) and U(10.2)-A(11.2), and a tetrauri