Gene Ontology annotation through association of InterPro records with GO terms
Structural basis for DNase activity of a conserved protein implicated in CRISPR-mediated genome defense.
Sequence- and structure-specific RNA processing by a CRISPR endonuclease.
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Csy4 is the endoribonuclease that produces mature crRNA in Pseudomonas aeruginosa
"we concluded that Csy4 is the endoribonuclease responsible for crRNA biogenesis"
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Cleavage is metal-ion independent
"CRISPR transcript cleavage is a rapid, metal ion-independent reaction"
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RNA recognition is sequence- and structure-specific, clamping the repeat hairpin
"the protein makes extensive interactions with the ssRNA-dsRNA junction at the base of the crRNA stem as well as with the major groove of the RNA hairpin"
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Catalysis and RNA binding are separable activities of the same protein
"Mutations of His 29 or Ser 148 (to alanine and cysteine, respectively) completely abolished cleavage activity without disrupting RNA binding"
Non-identity-mediated CRISPR-bacteriophage interaction mediated via the Csy and Cas3 proteins.
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Csy4 and Csy2 are strictly required for crRNA accumulation in vivo, whereas Csy1 and Csy3 are not
"proteins Csy4 and Csy2 are essential for small CRISPR RNA (crRNA) production in vivo, while the Csy1 and Csy3 proteins are not absolutely required for production of these small RNAs"
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The PA14 Yersinia-subtype locus was reported not to confer resistance to phage DMS3, acting instead on biofilm formation
"the Yersinia-subtype CRISPR region of Pseudomonas aeruginosa strain UCBPP-PA14 plays no detectable role in viral immunity but instead is required for bacteriophage DMS3-dependent inhibition of biofilm formation"
RNA-guided complex from a bacterial immune system enhances target recognition through seed sequence interactions.
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Csy1-4 assemble into a 350 kDa crRNA-containing surveillance complex
"the Csy proteins (Csy1-4) assemble into a 350 kDa ribonucleoprotein complex that facilitates target recognition by enhancing sequence-specific hybridization between the CRISPR RNA and complementary target sequences"
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Target recognition initiates at a seed sequence at the crRNA spacer 5' end
"Target recognition is enthalpically driven and localized to a "seed sequence" at the 5' end of the CRISPR RNA spacer"
Csy4 relies on an unusual catalytic dyad to position and cleave CRISPR RNA.
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Csy4 is the endoribonuclease that binds and cleaves the CRISPR repeat
"crRNA biogenesis requires the endoribonuclease Csy4, which binds and cleaves the repetitive sequence of the CRISPR transcript"
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Cleavage is a prerequisite for assembly of the Csy effector complex
"We show that this RNA cleavage step is essential for assembly of the Csy protein-crRNA complex that facilitates target recognition"
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Csy4 sequesters its own cleavage product rather than releasing it
"Considering that Csy4 recognizes a single cellular substrate and sequesters the cleavage product"
Bacteriophage genes that inactivate the CRISPR/Cas bacterial immune system.
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The PA14 type I-F locus restricts replication of CRISPR-sensitive phages
"The CRISPR-sensitive phages fail to replicate on PA14 due to the action of the CRISPR/Cas system14, but are able to replicate on PA14"
Multiple mechanisms for CRISPR-Cas inhibition by anti-CRISPR proteins.
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Anti-CRISPR proteins block the DNA-binding activity of the assembled type I-F complex by contacting different subunits
"Two block the DNA-binding activity of the CRISPR-Cas complex, yet do this by interacting with different protein subunits"
Foreign DNA acquisition by the I-F CRISPR-Cas system requires all components of the interference machinery.
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A Csy4 H29A catalytic mutant abolishes new spacer acquisition
"Deleting the csy3 gene (lane 6), or mutating the catalytic residue His29 of Csy4 nuclease (lane 7) that is needed for generation of mature crRNA also abolished spacer acquisition"
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Both naive and primed adaptation by the type I-F system require the intact Csy complex and crRNA
"both modes require, in addition to Cas1 and Cas2, intact Csy complex, an ortholog of the E. coli Cascade, and crRNA"
Inhibition mechanisms of AcrF9, AcrF8, and AcrF6 against type I-F CRISPR-Cas complex revealed by cryo-EM.
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Composition and stoichiometry of the type I-F Csy surveillance complex
"The Csy complex is comprised of four types of Cas proteins (Cas5f-8f) and a single 60-nt crRNA"
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Cas6f occupies the head of the spiral, with Cas5f and Cas8f in the tail and six Cas7f forming the backbone
"the maps exhibit an asymmetric spiral, with one Cas6f subunit in the head, one Cas5f and one Cas8f in the tail, and six Cas7f comprising the spiral backbone"