Gene Ontology annotation through association of InterPro records with GO terms
Combined Automated Annotation using Multiple IEA Methods
Structural basis for DNase activity of a conserved protein implicated in CRISPR-mediated genome defense.
-
Cas1 is a metal-dependent, DNA-specific endonuclease
"the Cas1 protein is a metal-dependent DNA-specific endonuclease that produces double-stranded DNA fragments of approximately 80 base pairs in length"
-
The crystal structure resolves a conserved divalent metal ion site
"The 2.2 A crystal structure of the Cas1 protein reveals a distinct fold and a conserved divalent metal ion-binding site"
-
Catalysis requires the metal site
"Mutation of metal ion-binding residues, chelation of metal ions, or metal-ion substitution inhibits Cas1-catalyzed DNA degradation"
-
cas1 is the only universally conserved cas gene
"cas1) encodes the only universally conserved protein component of CRISPR immune systems"
Bacteriophage genes that inactivate the CRISPR/Cas bacterial immune system.
-
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"
Foreign DNA acquisition by the I-F CRISPR-Cas system requires all components of the interference machinery.
-
A Cas1 D268A metal-site substitution abolishes new spacer acquisition
"This is an expected result since D268 is a conserved metal coordinating residue and substitution of the corresponding residue in E. coli Cas1 also abolishes adaptation"
-
Type I-F adaptation requires the intact Csy complex and crRNA in addition to Cas1 and Cas2
"both modes require, in addition to Cas1 and Cas2, intact Csy complex, an ortholog of the E. coli Cascade, and crRNA"
-
Cas1 and Cas2 are not required for the interference stage
"Cas1 and Cas2 are not required for CRISPR interference (22)"
-
In type I-F the cas2 and cas3 genes are fused, so there is no standalone Cas2 protein
"A specific feature of type I-F systems is a fusion of cas2 and cas3 homologs, which are encoded on separate genes in other CRISPR"