The proteins listed below share a common architecture with a protein kinase
homology domain (see <PDOC00100>) followed by an ~135-residue globular kinase-extension nuclease (KEN) domain made of eight helices (see <PDB:2RIO>) :
Mammalian 2-5A-dependent RNase or RNase L (EC 3.1.26.-), an interferon-
induced enzyme implicated in both the molecular mechanisms of interferon
action and the fundamental control of RNA stability. 2-5A-dependent RNase
is a unique enzyme in that it requires 2-5A, unusual oligoadenylates with
2',5'-phosphodiester linkages. RNase L is catalytically active only after
binding to an unusual activator molecule containing a 5'-phosphorylated 2',
5'-linked oligoadenylate (2-5A), in the N-terminal half. RNase L consists
of three domains, namely the N-terminal ankyrin repeat domain (see
<PDOC50088>), the protein kinase homology domain, and the C-terminal KEN
Eukaryotic Ire1/Ern1, an ancient transmembrane sensor of endoplasmic
reticulum (ER) stress with dual protein kinase and ribonuclease activities.
In repsonse to ER stress Ire1/Ern1 catalyzes the splicing of target mRNAs
in a spliceosome-independent manner. Ire1/Ern1 is a type 1 transmembrane
receptor consisting of an N-terminal ER luminal domain, a transmembrane
segment and a cytoplasmic region. The cytoplasmic region encompasses a
protein kinase domain followed by a C-terminal KEN domain [1,5].
The dimerization of the kinase domain activates the ribonuclease function of
the KEN domain .
The profile we developed covers the entire KEN domain.
July 2008 / First entry.
PROSITE method (with tools and information) covered by this documentation:
Lee K.P.K. Dey M. Neculai D. Cao C. Dever T.E. Sicheri F.
Structure of the dual enzyme Ire1 reveals the basis for catalysis and regulation in nonconventional RNA splicing.
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