Conformation and properties of hammerhead-type RNA enzymes.

We designed a hammerhead-type RNA enzyme system which consists of three ribooligonucleotide strands (1-3), synthesized these oligomers and their analogues, and examined conformation and properties of the RNA complexes. Imino proton NMR spectra of the complexes were measured and the signals were assigned by comparison with the spectra of some model duplexes. Examination of a complex containing a G----I mutation (Y = I) revealed that the 2-amino group of the third guanosine residue in the loop 1 (L1) plays an important role for maintaining both the activity and loop conformation.