scholarly journals A bacterial Argonaute with noncanonical guide RNA specificity

2016 ◽  
Vol 113 (15) ◽  
pp. 4057-4062 ◽  
Author(s):  
Emine Kaya ◽  
Kevin W. Doxzen ◽  
Kilian R. Knoll ◽  
Ross C. Wilson ◽  
Steven C. Strutt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Site ◽  
Sequence Alignment ◽  
Small Rna ◽  
Guide Strand ◽  
Guide Rna ◽  
Guide Rnas ◽  
Mrna Targets ◽  
Argonaute Proteins ◽  
Rna Complex

Eukaryotic Argonaute proteins induce gene silencing by small RNA-guided recognition and cleavage of mRNA targets. Although structural similarities between human and prokaryotic Argonautes are consistent with shared mechanistic properties, sequence and structure-based alignments suggested that Argonautes encoded within CRISPR-cas [clustered regularly interspaced short palindromic repeats (CRISPR)-associated] bacterial immunity operons have divergent activities. We show here that the CRISPR-associated Marinitoga piezophila Argonaute (MpAgo) protein cleaves single-stranded target sequences using 5′-hydroxylated guide RNAs rather than the 5′-phosphorylated guides used by all known Argonautes. The 2.0-Å resolution crystal structure of an MpAgo–RNA complex reveals a guide strand binding site comprising residues that block 5′ phosphate interactions. Using structure-based sequence alignment, we were able to identify other putative MpAgo-like proteins, all of which are encoded within CRISPR-cas loci. Taken together, our data suggest the evolution of an Argonaute subclass with noncanonical specificity for a 5′-hydroxylated guide.

scholarly journals Human Argonaute2 and Argonaute3 are catalytically activated by different lengths of guide RNA

2020 ◽  
Author(s):  
Mi Seul Park ◽  
GeunYoung Sim ◽  
Audrey C. Kehling ◽  
Kotaro Nakanishi
Keyword(s):  
Gene Silencing ◽  
Fold Increase ◽  
Specific Gene ◽  
Small Interfering Rnas ◽  
Guide Rna ◽  
Guide Rnas ◽  
Argonaute Proteins ◽  
Complementary Rnas ◽  
Standing Question

AbstractRNA interfering is a eukaryote-specific gene silencing by 20∼23 nucleotide (nt) microRNAs and small interfering RNAs that recruit Argonaute proteins to complementary RNAs for degradation. In humans, Argonaute2 (AGO2) has been known as the only slicer while Argonaute3 (AGO3) barely cleaves RNAs. Therefore, the intrinsic slicing activity of AGO3 remains controversial and a long-standing question. Here, we report 14-nt 3′ end-shortened variants of let-7a, miR-27a, and specific miR-17-92 families that make AGO3 an extremely competent slicer by an ∼ 82-fold increase in target cleavage. These RNAs, named cleavage-inducing tiny guide RNAs (cityRNAs), conversely lower the activity of AGO2, demonstrating that AGO2 and AGO3 have different optimum guide lengths for target cleavage. Our study sheds light on the role of tiny guide RNAs.

scholarly journals The Mechanism Selecting the Guide Strand from Small RNA Duplexes is Different Among Argonaute Proteins

2008 ◽  
Vol 49 (4) ◽  
pp. 493-500 ◽  
Author(s):  
Atsushi Takeda ◽  
Shintaro Iwasaki ◽  
Toshiaki Watanabe ◽  
Maki Utsumi ◽  
Yuichiro Watanabe
Keyword(s):  
Small Rna ◽  
Guide Strand ◽  
Argonaute Proteins ◽  
Rna Duplexes

scholarly journals Human Argonaute2 and Argonaute3 are catalytically activated by different lengths of guide RNA

2020 ◽  
Vol 117 (46) ◽  
pp. 28576-28578
Author(s):  
Mi Seul Park ◽  
GeunYoung Sim ◽  
Audrey C. Kehling ◽  
Kotaro Nakanishi
Keyword(s):  
Gene Silencing ◽  
Specific Gene ◽  
Small Interfering Rnas ◽  
Guide Rna ◽  
Guide Rnas ◽  
Argonaute Proteins ◽  
Rna Interfering ◽  
Complementary Rnas ◽  
Standing Question

RNA interfering is a eukaryote-specific gene silencing by 20∼23-nucleotide (nt) microRNAs and small interfering RNAs that recruit Argonaute proteins to complementary RNAs for degradation. In humans, Argonaute2 (AGO2) has been known as the only slicer while Argonaute3 (AGO3) barely cleaves RNAs. Therefore, the intrinsic slicing activity of AGO3 remains controversial and a long-standing question. Here, we report 14-nt 3′ end-shortened variants of let-7a, miR-27a, and specific miR-17–92 families that make AGO3 an extremely competent slicer, increasing target cleavage up to ∼82-fold in some instances. These RNAs, named cleavage-inducing tiny guide RNAs (cityRNAs), conversely lower the activity of AGO2, demonstrating that AGO2 and AGO3 have different optimum guide lengths for target cleavage. Our study sheds light on the role of tiny guide RNAs.

scholarly journals Recognition of the small regulatory RNA RydC by the bacterial Hfq protein

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Daniela Dimastrogiovanni ◽  
Kathrin S Fröhlich ◽  
Katarzyna J Bandyra ◽  
Heather A Bruce ◽  
Susann Hohensee ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Small Rna ◽  
Small Rnas ◽  
Regulatory Networks ◽  
Target Recognition ◽  
Seed Region ◽  
Regulatory Rna ◽  
E Coli ◽  
Small Regulatory Rna ◽  
Rna Complex

Bacterial small RNAs (sRNAs) are key elements of regulatory networks that modulate gene expression. The sRNA RydC of Salmonella sp. and Escherichia coli is an example of this class of riboregulators. Like many other sRNAs, RydC bears a ‘seed’ region that recognises specific transcripts through base-pairing, and its activities are facilitated by the RNA chaperone Hfq. The crystal structure of RydC in complex with E. coli Hfq at a 3.48 Å resolution illuminates how the protein interacts with and presents the sRNA for target recognition. Consolidating the protein–RNA complex is a host of distributed interactions mediated by the natively unstructured termini of Hfq. Based on the structure and other data, we propose a model for a dynamic effector complex comprising Hfq, small RNA, and the cognate mRNA target.

ASSESSMENT OF EFFICIENCY AND OFF-TARGET ACTIVITY OF CRISPR/CAS RIBONUCLEOPROTEIN COMPLEXES

2020 ◽  
Author(s):  
Y.V. Mikhaylova ◽  
◽  
M.A. Tyumentseva ◽  
A.A. Shelenkov ◽  
Y.G. Yanushevich ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Correct Choice ◽  
Target Sequence ◽  
Dna Breaks ◽  
Gene Encoding ◽  
Guide Rna ◽  
Guide Rnas ◽  
Ribonucleoprotein Complexes ◽  
Chemokine Receptor Ccr5 ◽  
Target Activity

In this study, we assessed the efficiency and off-target activity of the CRISPR/CAS complex with one of the selected guide RNAs using the CIRCLE-seq technology. The gene encoding the human chemokine receptor CCR5 was used as a target sequence for genome editing. The results of this experiment indicate the correct choice of the guide RNA and efficient work of the CRISPR- CAS ribonucleoprotein complex used. CIRCLE-seq technology has shown high sensitivity compared to bioinformatic methods for predicting off-target activity of CRISPR/CAS complexes. We plan to evaluate the efficiency and off-target activity of CRISPR/CAS ribonucleoprotein complexes with other guide RNAs by slightly adjusting the CIRCLE-seq-technology protocol in order to reduce nonspecific DNA breaks and increase the number of reliable reads.

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