scholarly journals Conserved DNA motifs in the type II-A CRISPR leader region

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3161 ◽  
Author(s):  
Mason J. Van Orden ◽  
Peter Klein ◽  
Kesavan Babu ◽  
Fares Z. Najar ◽  
Rakhi Rajan
Keyword(s):  
Protein Complexes ◽  
Streptococcus Thermophilus ◽  
Type Ii ◽  
Leader Region ◽  
Dna Motifs ◽  
Motif Clustering ◽  
End Sequences ◽  
Repeat Junction ◽  
Rna Protein Complexes ◽  
Cas Proteins

The Clustered Regularly Interspaced Short Palindromic Repeats associated (CRISPR-Cas) systems consist of RNA-protein complexes that provide bacteria and archaea with sequence-specific immunity against bacteriophages, plasmids, and other mobile genetic elements. Bacteria and archaea become immune to phage or plasmid infections by inserting short pieces of the intruder DNA (spacer) site-specifically into the leader-repeat junction in a process called adaptation. Previous studies have shown that parts of the leader region, especially the 3′ end of the leader, are indispensable for adaptation. However, a comprehensive analysis of leader ends remains absent. Here, we have analyzed the leader, repeat, and Cas proteins from 167 type II-A CRISPR loci. Our results indicate two distinct conserved DNA motifs at the 3′ leader end: ATTTGAG (noted previously in the CRISPR1 locus ofStreptococcus thermophilusDGCC7710) and a newly defined CTRCGAG, associated with the CRISPR3 locus ofS. thermophilusDGCC7710. A third group with a very short CG DNA conservation at the 3′ leader end is observed mostly in lactobacilli. Analysis of the repeats and Cas proteins revealed clustering of these CRISPR components that mirrors the leader motif clustering, in agreement with the coevolution of CRISPR-Cas components. Based on our analysis of the type II-A CRISPR loci, we implicate leader end sequences that could confer site-specificity for the adaptation-machinery in the different subsets of type II-A CRISPR loci.

scholarly journals CRISPR DNA elements controlling site-specific spacer integration and proper repeat length by a Type II CRISPR–Cas system

2019 ◽  
Vol 47 (16) ◽  
pp. 8632-8648 ◽  
Author(s):  
Jenny G Kim ◽  
Sandra Garrett ◽  
Yunzhou Wei ◽  
Brenton R Graveley ◽  
Michael P Terns
Keyword(s):  
Dna Sequences ◽  
High Specificity ◽  
Streptococcus Thermophilus ◽  
Transesterification Reaction ◽  
Hydroxyl Groups ◽  
Type Ii ◽  
Site Specific ◽  
Crispr Locus ◽  
Dna Elements ◽  
Repeat Junction

Abstract CRISPR–Cas systems provide heritable immunity against viruses by capturing short invader DNA sequences, termed spacers, and incorporating them into the CRISPR loci of the prokaryotic host genome. Here, we investigate DNA elements that control accurate spacer uptake in the type II-A CRISPR locus of Streptococcus thermophilus. We determined that purified Cas1 and Cas2 proteins catalyze spacer integration with high specificity for CRISPR repeat junctions. We show that 10 bp of the CRISPR leader sequence is critical for stimulating polarized integration preferentially at the repeat proximal to the leader. Spacer integration proceeds through a two-step transesterification reaction where the 3′ hydroxyl groups of the spacer target both repeat borders on opposite strands. The leader-proximal end of the repeat is preferentially targeted for the first site of integration through recognition of sequences spanning the leader-repeat junction. Subsequently, second-site integration at the leader-distal end of the repeat is specified by multiple determinants including a length-defining mechanism relying on a repeat element proximal to the second site of integration. Our results highlight the intrinsic ability of type II Cas1/Cas2 proteins to coordinate directional and site-specific spacer integration into the CRISPR locus to ensure precise duplication of the repeat required for CRISPR immunity.

scholarly journals Alu RNA-protein complexes formed in vitro react with a novel lupus autoantibody.

1985 ◽  
Vol 260 (21) ◽  
pp. 11781-11786
Author(s):  
R Kole ◽  
L D Fresco ◽  
J D Keene ◽  
P L Cohen ◽  
R A Eisenberg ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Alu Rna ◽  
Rna Protein Complexes

scholarly journals Arabidopsis thaliana G3BP Ortholog Rescues Mammalian Stress Granule Phenotype across Kingdoms

2021 ◽  
Vol 22 (12) ◽  
pp. 6287
Author(s):  
Hendrik Reuper ◽  
Benjamin Götte ◽  
Lucy Williams ◽  
Timothy J. C. Tan ◽  
Gerald M. McInerney ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Fusion Proteins ◽  
Biological Function ◽  
Protein Complexes ◽  
Protein Family ◽  
Knock Out ◽  
Marker Proteins ◽  
Interaction Partners ◽  
Functional Analyses ◽  
Rna Protein Complexes

Stress granules (SGs) are dynamic RNA–protein complexes localized in the cytoplasm that rapidly form under stress conditions and disperse when normal conditions are restored. The formation of SGs depends on the Ras-GAP SH3 domain-binding protein (G3BP). Formations, interactions and functions of plant and human SGs are strikingly similar, suggesting a conserved mechanism. However, functional analyses of plant G3BPs are missing. Thus, members of the Arabidopsis thaliana G3BP (AtG3BP) protein family were investigated in a complementation assay in a human G3BP knock-out cell line. It was shown that two out of seven AtG3BPs were able to complement the function of their human homolog. GFP-AtG3BP fusion proteins co-localized with human SG marker proteins Caprin-1 and eIF4G1 and restored SG formation in G3BP double KO cells. Interaction between AtG3BP-1 and -7 and known human G3BP interaction partners such as Caprin-1 and USP10 was also demonstrated by co-immunoprecipitation. In addition, an RG/RGG domain exchange from Arabidopsis G3BP into the human G3BP background showed the ability for complementation. In summary, our results support a conserved mechanism of SG function over the kingdoms, which will help to further elucidate the biological function of the Arabidopsis G3BP protein family.

scholarly journals Isolation of Endogenously Assembled RNA-Protein Complexes Using Affinity Purification Based on Streptavidin Aptamer S1

2015 ◽  
Vol 16 (9) ◽  
pp. 22456-22472 ◽  
Author(s):  
Yangchao Dong ◽  
Jing Yang ◽  
Wei Ye ◽  
Yuan Wang ◽  
Chuantao Ye ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Affinity Purification ◽  
Streptavidin Aptamer ◽  
Rna Protein Complexes

scholarly journals Bioinformatics Tools and Benchmarks for Computational Docking and 3D Structure Prediction of RNA-Protein Complexes

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 432 ◽  
Author(s):  
Chandran Nithin ◽  
Pritha Ghosh ◽  
Janusz Bujnicki
Keyword(s):  
Rna Splicing ◽  
Structure Prediction ◽  
Protein Complexes ◽  
3D Structure ◽  
Structural Models ◽  
Computational Prediction ◽  
Computational Docking ◽  
3D Structure Prediction ◽  
Rna Protein Complexes

RNA-protein (RNP) interactions play essential roles in many biological processes, such as regulation of co-transcriptional and post-transcriptional gene expression, RNA splicing, transport, storage and stabilization, as well as protein synthesis. An increasing number of RNP structures would aid in a better understanding of these processes. However, due to the technical difficulties associated with experimental determination of macromolecular structures by high-resolution methods, studies on RNP recognition and complex formation present significant challenges. As an alternative, computational prediction of RNP interactions can be carried out. Structural models obtained by theoretical predictive methods are, in general, less reliable compared to models based on experimental measurements but they can be sufficiently accurate to be used as a basis for to formulating functional hypotheses. In this article, we present an overview of computational methods for 3D structure prediction of RNP complexes. We discuss currently available methods for macromolecular docking and for scoring 3D structural models of RNP complexes in particular. Additionally, we also review benchmarks that have been developed to assess the accuracy of these methods.

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