Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
0  structures 41  species 0  interactions 43  sequences 1  architecture

Family: Cas6 (PF09559)

Summary: Cas6 Crispr

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Cas6 Crispr Provide feedback

The Cas6 Crispr family of proteins averaging 140 residues are characterised by having a GhGxxxxxGhG motif, where h indicates a hydrophobic residue, at the C-terminus [1]. The CRISPR-Cas system is possibly a mechanism of defence against invading pathogens and plasmids that functions analogously to the RNA interference (RNAi) systems in eukaryotes [2].

Literature references

  1. Haft DH, Selengut J, Mongodin EF, Nelson KE; , PLoS Comput Biol. 2005;1:e60.: A guild of 45 CRISPR-associated (Cas) protein families and multiple CRISPR/Cas subtypes exist in prokaryotic genomes. PUBMED:16292354 EPMC:16292354

  2. Makarova KS, Grishin NV, Shabalina SA, Wolf YI, Koonin EV; , Biol Direct. 2006;1:7.: 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. PUBMED:16545108 EPMC:16545108


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR014174

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 [PUBMED:17442114]. CRISPRs appear to provide acquired resistance against bacteriophages, possibly acting with an RNA interference-like mechanism to inhibit gene functions of invasive DNA elements [PUBMED:17379808, PUBMED:16545108]. Differences in the number and type of spacers between CRISPR repeats correlate with phage sensitivity. It is thought that following phage infection, bacteria integrate new spacers derived from phage genomic sequences, and that the removal or addition of particular spacers modifies the phage-resistance phenotype of the cell. Therefore, the specificity of CRISPRs may be determined by spacer-phage sequence similarity.

In addition, there are many protein families known as CRISPR-associated sequences (Cas), which are encoded in the vicinity of CRISPR loci [PUBMED:16292354]. CRISPR/cas gene regions can be quite large, with up to 20 different, tandem-arranged cas genes next to a CRISPR cluster or filling the region between two repeat clusters. Cas genes and CRISPRs are found on mobile genetic elements such as plasmids, and have undergone extensive horizontal transfer. Cas proteins are thought to be involved in the propagation and functioning of CRISPRs. Some Cas proteins show similarity to helicases and repair proteins, although the functions of most are unknown. Cas families can be divided into subtypes according to operon organisation and phylogeny.

Members of this entry resemble the Cas6 proteins described by INTERPRO in having a C-terminal motif GXGXXXXXGXG, where the single X of each GXG is hydrophobic and the spacer XXXXX has at least one Lys or Arg. Examples are found in cas gene operons of CRISPR regions in Anabaena variabilis (strain ATCC 29413/PCC 7937), Leptospira interrogans, Gemmata obscuriglobus UQM 2246, and twice in Myxococcus xanthus (strain DK 1622). Oddly, an orphan member is found in Thiobacillus denitrificans (strain ATCC 25259), whose genome does not seem to contain other evidence of CRISPR repeats or cas genes.

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

Loading domain graphics...

Pfam Clan

This family is a member of clan RAMPS-Cas5-like (CL0362), which contains the following 7 members:

Cas6 Cas_Cas5d Cas_Cas6 Cas_Cmr3 CRISPR_assoc DUF2276 RAMPs

Alignments

We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

View options

We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

  Seed
(10)
Full
(43)
Representative proteomes NCBI
(51)
Meta
(26)
RP15
(10)
RP35
(17)
RP55
(19)
RP75
(20)
Jalview View  View  View  View  View  View  View  View 
HTML View  View  View  View  View  View     
PP/heatmap 1 View  View  View  View  View     
Pfam viewer View  View             

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(10)
Full
(43)
Representative proteomes NCBI
(51)
Meta
(26)
RP15
(10)
RP35
(17)
RP55
(19)
RP75
(20)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(10)
Full
(43)
Representative proteomes NCBI
(51)
Meta
(26)
RP15
(10)
RP35
(17)
RP55
(19)
RP75
(20)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

Pfam alignments:

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: TIGRFAMs
Previous IDs: none
Type: Family
Author: TIGRFAMs, Coggill P
Number in seed: 10
Number in full: 43
Average length of the domain: 199.20 aa
Average identity of full alignment: 32 %
Average coverage of the sequence by the domain: 90.31 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 22.8 22.8
Trusted cut-off 27.2 121.9
Noise cut-off 22.7 22.7
Model length: 195
Family (HMM) version: 5
Download: download the raw HMM for this family

Species distribution

Sunburst controls

Show

This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

Loading sunburst data...

Tree controls

Hide

The tree shows the occurrence of this domain across different species. More...

Loading...

Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.