PROSITE documentation PDOC51643
HD Cas3-type domain profile


Clustered regularly interspaced short palindromic repeats (CRISPRs) and Cas proteins represents an adaptative microbial immunity system against viruses and plasmids. Cas3 proteins have been proposed to play a key role in the CRISPR mechanism through the direct cleavage of invasive nucleic acids. Cas3 proteins are predicted to contain the DExD/H-box helicase (see <PDOC51192>) and HD domains, which can be covalently fused (Cas3) or encoded as individual proteins (Cas3' or Cas3'', respectively). The HD domain proteins represent a large group of enzymes, which catalyze phosphomonoesterase or phosphodiesterase reactions on a broad range of substrates including nucleotides and nucleic acids and function primarily in nucleic acid metabolism and signal transduction. The Cas3-type HD domain has nuclease activity against ssDNA and ssRNA [1,2].

The globular Cas3-type HD domain is composed of eigth α-helices and two short β-strands connected by extended loops (see <PDB:3S4L>) [2].

The profile we developed covers the entire Cas3-type HD domain.

Last update:

April 2012 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

HD_CAS3, PS51643; HD Cas3-type domain profile  (MATRIX)


1AuthorsSinkunas T. Gasiunas G. Fremaux C. Barrangou R. Horvath P. Siksnys V.
TitleCas3 is a single-stranded DNA nuclease and ATP-dependent helicase in the CRISPR/Cas immune system.
SourceEMBO J. 30:1335-1342(2011).
PubMed ID21343909

2AuthorsBeloglazova N. Petit P. Flick R. Brown G. Savchenko A. Yakunin A.F.
TitleStructure and activity of the Cas3 HD nuclease MJ0384, an effector enzyme of the CRISPR interference.
SourceEMBO J. 30:4616-4627(2011).
PubMed ID22009198

PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see prosite_license.html.


View entry in original PROSITE document format
View entry in raw text format (no links)