The hairpin ribozyme: from crystal structure to function.
The hairpin ribozyme is one of four known natural catalytic RNAs that carry out sequence-specific cleavage of RNA. It is of particular biochemical interest because, unlike 'classic' ribozymes, such as the group I intron, it appears not to employ metal ions as catalytic cofactors. We have determined the crystal structure of a hairpin-ribozyme-inhibitor complex at a resolution of 2.4 A. The active site of the ribozyme results from docking of two irregular double helices. Docking results in major structural rearrangements of the helices, including a distortion of the substrate strand that brings it into a reactive conformation. It remains to be established whether this RNA enzyme relies exclusively on binding energy to carry out catalysis, or whether some other mechanism, such as general acid-base catalysis, is being employed.
Ferré-D'amaré
A R
AR
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., Seattle, WA 98109-1024, USA. aferre@fhcrc.org
Rupert
P B
PB
D020134:Catalytic Domain; D008956:Models, Chemical; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012313:RNA / Q000378:metabolism; D016337:RNA, Catalytic / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D016337:RNA, Catalytic; C418481:hairpin ribozyme; D012313:RNA