Dicer
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Dicer is a ribonuclease in the RNase III family that cleaves double-stranded RNA (dsRNA) and pre-microRNA (miRNA) into short double-stranded RNA fragments called small interfering RNA (siRNA) about 20-25 nucleotides long, usually with a two-base overhang on the 3' end. Dicer contains two RNase III domains and one PAZ domain; the distance between these two regions of the molecule is determined by the length and angle of the connector helix and determines the length of the siRNAs it produces.[1] Dicer catalyzes the first step in the RNA interference pathway and initiates formation of the RNA-induced silencing complex (RISC), whose catalytic component argonaute is an endonuclease capable of degrading messenger RNA (mRNA) whose sequence is complementary to that of the siRNA guide strand.[2]
[edit] History
Dicer was given its name by Emily Bernstein, a graduate student in Greg Hannon's group at the Cold Spring Harbor Laboratory, who first demonstrated the enzyme's dsRNA "dicing" activity.[3]
[edit] References
- ^ a b Macrae I, Zhou K, Li F, Repic A, Brooks A, Cande W, Adams P, Doudna J (2006). "Structural basis for double-stranded RNA processing by Dicer". Science 311 (5758): 195-8. PMID 16410517.
- ^ Jaronczyk K, Carmichael J, Hobman T (2005). "Exploring the functions of RNA interference pathway proteins: some functions are more RISCy than others?". Biochem J 387 (Pt 3): 561-71. PMID 15845026.
- ^ Bernstein E, Caudy A, Hammond S, Hannon G (2001). "Role for a bidentate ribonuclease in the initiation step of RNA interference". Nature 409 (6818): 363-6. PMID 11201747.