InterPro : IPR002729

Name  CRISPR-associated protein Cas1 Short Name  CRISPR-assoc_Cas1
Type  Family Description  The CRISPR-Cas system is a prokaryotic defense mechanism against foreign genetic elements. The key elements of this defense system are the Cas proteins and the CRISPR RNA. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) are a family of DNA direct repeats separated by regularly sized non-repetitive spacer sequences that are found in most bacterial and archaeal genomes []. CRISPRs appear to provide acquired resistance against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain sequences complementary to antecedent mobile elements and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA).The defense reaction is divided into three stages. In the adaptation stage, the invader DNA is cleaved, and a piece of it is selected to be integrated as a new spacer into the CRISPR locus, where it is stored as an identity tag for future attacks by this invader. During the second stage (the expression stage), the CRISPR RNA (pre-crRNA) is transcribed and subsequently processed into the mature crRNAs. In the third stage (the interference stage), Cas proteins, together with crRNAs, identify and degrade the invader [, , ].The CRISPR-Cas systems have been sorted into three major classes. In CRISPR-Cas types I and III, the mature crRNA is generally generated by a member of the Cas6 protein family. Whereas in system III the Cas6 protein acts alone, in some class I systems it is part of a complex of Cas proteins known as Cascade (CRISPR-associated complex for antiviral defense). The Cas6 protein is necessary for crRNA production whereas the additional Cas proteins that form the Cascade complex are needed for crRNA stability []. This entry represents Cas1, which is a metal-dependent DNA-specific endonuclease []. Cas1 may play a role in the recognition, cleavage, and/or integration of foreign nucleic acids into CRISPRs.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



8 Child Features

Id Name Short Name Type
IPR019855 CRISPR-associated protein Cas1, NMENI subtype CRISPR-assoc_Cas1_NMENI Family
IPR019856 CRISPR-associated protein Cas1, DVULG subtype CRISPR-assoc_Cas1_DVULG Family
IPR019857 CRISPR-associated protein Cas1, YPEST subtype CRISPR-assoc_Cas1_YPEST-subtyp Family
IPR019858 CRISPR-associated protein Cas1, HMARI/TNEAP subtype CRISPR-assoc_Cas1_HMARI/TNEAP Family
IPR023843 CRISPR-associated protein Cas1, cyanobacteria-type CRISPR-assoc_Cas1_cyanobact Family
IPR023844 CRISPR-associated protein Cas1, MYXAN subtype CRISPR-assoc_Cas1_MYXAN Family
IPR027617 CRISPR-associated endonuclease Cas1, PREFRAN subtype Cas1_PREFRAN Family
IPR019851 CRISPR-associated protein Cas1, ECOLI subtype CRISPR-assoc_Cas1_ECOLI Family

0 Contains

0 Found In

0 Parent Features

6 Publications

First Author Title Year Journal Volume Pages
Kunin V Evolutionary conservation of sequence and secondary structures in CRISPR repeats. 2007 Genome Biol 8 R61
Barrangou R CRISPR provides acquired resistance against viruses in prokaryotes. 2007 Science 315 1709-12
Makarova KS A putative RNA-interference-based immune system in prokaryotes: computational analysis of the predicted enzymatic machinery, functional analogies with eukaryotic RNAi, and hypothetical mechanisms of action. 2006 Biol Direct 1 7
Wiedenheft B Structural basis for DNase activity of a conserved protein implicated in CRISPR-mediated genome defense. 2009 Structure 17 904-12
Howard JA Helicase dissociation and annealing of RNA-DNA hybrids by Escherichia coli Cas3 protein. 2011 Biochem J 439 85-95
Brendel J A complex of Cas proteins 5, 6, and 7 is required for the biogenesis and stability of clustered regularly interspaced short palindromic repeats (crispr)-derived rnas (crrnas) in Haloferax volcanii. 2014 J Biol Chem 289 7164-77

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)