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2goz
From Proteopedia
The 2.2 A structure of a full-length catalytically active hammerhead ribozyme
Overview
Minimal hammerhead ribozymes have been characterized extensively by static and time-resolved crystallography as well as numerous biochemical analyses, leading to mutually contradictory mechanistic explanations for catalysis. We present the 2.2 A resolution crystal structure of a full-length Schistosoma mansoni hammerhead ribozyme that permits us to explain the structural basis for its 1000-fold catalytic enhancement. The full-length hammerhead structure reveals how tertiary interactions occurring remotely from the active site prime this ribozyme for catalysis. G-12 and G-8 are positioned consistent with their previously suggested roles in acid-base catalysis, the nucleophile is aligned with a scissile phosphate positioned proximal to the A-9 phosphate, and previously unexplained roles of other conserved nucleotides become apparent within the context of a distinctly new fold that nonetheless accommodates the previous structural studies. These interactions permit us to explain the previously irreconcilable sets of experimental results in a unified, consistent, and unambiguous manner.
About this Structure
Full crystallographic information is available from OCA.
Reference
Tertiary contacts distant from the active site prime a ribozyme for catalysis., Martick M, Scott WG, Cell. 2006 Jul 28;126(2):309-20. Epub 2006 Jul 20. PMID:16859740 Page seeded by OCA on Sun May 4 05:21:14 2008
