Publication Date:
2012-06-23
Description:
The RNA-induced silencing complex, comprising Argonaute and guide RNA, mediates RNA interference. Here we report the 3.2 A crystal structure of Kluyveromyces polysporus Argonaute (KpAGO) fortuitously complexed with guide RNA originating from small-RNA duplexes autonomously loaded by recombinant KpAGO. Despite their diverse sequences, guide-RNA nucleotides 1-8 are positioned similarly, with sequence-independent contacts to bases, phosphates and 2'-hydroxyl groups pre-organizing the backbone of nucleotides 2-8 in a near-A-form conformation. Compared with prokaryotic Argonautes, KpAGO has numerous surface-exposed insertion segments, with a cluster of conserved insertions repositioning the N domain to enable full propagation of guide-target pairing. Compared with Argonautes in inactive conformations, KpAGO has a hydrogen-bond network that stabilizes an expanded and repositioned loop, which inserts an invariant glutamate into the catalytic pocket. Mutation analyses and analogies to ribonuclease H indicate that insertion of this glutamate finger completes a universally conserved catalytic tetrad, thereby activating Argonaute for RNA cleavage.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853139/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853139/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nakanishi, Kotaro -- Weinberg, David E -- Bartel, David P -- Patel, Dinshaw J -- AI068776/AI/NIAID NIH HHS/ -- GM61835/GM/NIGMS NIH HHS/ -- R01 AI068776/AI/NIAID NIH HHS/ -- R01 GM061835/GM/NIGMS NIH HHS/ -- R37 GM061835/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2012 Jun 20;486(7403):368-74. doi: 10.1038/nature11211.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22722195" target="_blank"〉PubMed〈/a〉
Keywords:
Argonaute Proteins/*chemistry/*metabolism
;
Base Sequence
;
Biocatalysis
;
Catalytic Domain
;
Crystallography, X-Ray
;
Eukaryotic Cells/chemistry/enzymology
;
Fungal Proteins/*chemistry/*metabolism
;
Kluyveromyces/*chemistry/enzymology
;
Models, Molecular
;
Molecular Conformation
;
Molecular Sequence Data
;
RNA, Guide/*chemistry/genetics/*metabolism
;
Saccharomycetales/enzymology/genetics
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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