tokens: The ability of U6-U57 mutants to influence the fidelity of both branch site and 3 ' splice site recognition suggests that this nucleotide may participate in the formation of the active site ( s ) of the spliceosome .
folded_tokens: the ability of u6-u57 mutant to influence the fidelity of both branch site and 3 ' splice site recognition suggest that this nucleotide may participate in the formation of the active site ( s ) of the spliceosome .