PROSITE documentation PDOC51749
Cas9-type HNH domain profile


The CRISPR (clustered regularly interspaced short palindromic repeat)-Cas (CRISPR associated) system is a naturally occuring, adaptative microbial immune system for defense against invading phages and other mobile genetic elements. Type II CRISPR-Cas systems use an RNA-guided DNA endonuclease, Cas9, to generate double strand breaks in invasive DNA during an adaptative bacterial immune response. Cas9 proteins are abundant across the bacterial kingdom, but vary widely in both sequence and size. All known Cas9 enzymes contain an HNH domain that cleaves the DNA strand complementary to the guide RNA sequence (target strand), and a RuvC nuclease domain required for cleaving the noncomplementary strand (non-target strand), yielding double strand DNA breaks (DSBs) [1,2].

The Cas9-type HNH nuclease domain contains a two-stranded antiparallel β sheet flanked by two α-helices on each side (see <PDB:4CMP>) [1,2].

The profile we developed covers the entire Cas9-type HNH domain.

Last update:

March 2015 / First entry.


Technical section

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

HNH_CAS9, PS51749; Cas9-type HNH domain profile  (MATRIX)


1AuthorsJinek M. Jiang F. Taylor D.W. Sternberg S.H. Kaya E. Ma E. Anders C. Hauer M. Zhou K. Lin S. Kaplan M. Iavarone A.T. Charpentier E. Nogales E. Doudna J.A.
TitleStructures of Cas9 endonucleases reveal RNA-mediated conformational activation.
SourceScience 343:1247997-1247997(2014).
PubMed ID24505130

2AuthorsNishimasu H. Ran F.A. Hsu P.D. Konermann S. Shehata S.I. Dohmae N. Ishitani R. Zhang F. Nureki O.
TitleCrystal structure of Cas9 in complex with guide RNA and target DNA.
SourceCell 156:935-949(2014).
PubMed ID24529477

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