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RNase III enzymes and the initiation of gene silencing


Our understanding of RNA interference has been enhanced by new data concerning RNase III molecules. The role of Dicer has previously been established in RNAi as the originator of 22-mers characteristic of silencing phenomena. Recently, a related RNAse III enzyme, Drosha, has surfaced as another component of the RNAi pathway. In addition to biochemistry, protein structures have proven to be helpful in deciphering the enzymology of RNase III molecules.

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Figure 1: Domain structures of class I–III RNase III proteins.
Figure 2: Models for Dicer cleavage.


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We thank P. Paddison and X. Ji for helpful discussion. We thank M. Zhou and M. Sattler for sharing their results prior to publication. We also thank L. He, D. Siolas, J. Liu, A. Denli, and L. Murchison for critical reading of the manuscript.

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Correspondence to Gregory J Hannon.

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Carmell, M., Hannon, G. RNase III enzymes and the initiation of gene silencing. Nat Struct Mol Biol 11, 214–218 (2004).

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