|Family type peptidase||C87.001 - nairovirus deubiquitinylating peptidase (Crimean-Congo hemorrhagic fever virus), MEROPS Accession MER0100000 (peptidase unit: 35-153)|
|Content of family||Peptidase family C87 contains viral isopeptidases.|
Identifier created: MEROPS 8.00A (14 February 2008)|
As reviewed by Arguello & Hiscott (2007), an aspect of the cellular response to viral infection is the production of type I interferon (IFN), a family of cytokines that signals through its cognate IFN receptors and the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, leading to the expression of hundreds of genes with antiviral activity. Detection of viral components by the Toll-like receptor (TLR) system or the cytoplasmic RNA helicases RIG-I and Mda5 activates the IFN pathway by signaling to the kinases IKKepsilon/TBK1 to phosphorylate interferon regulatory factors 3 and 7 (IRF3/IRF7) and induce expression of IFN and IFN-stimulated genes (ISGs). Simultaneously, the inflammatory response is triggered through the IkappaB kinase (IKK) complex, leading to proteasomal degradation of the inhibitor of NF-kappaB (IkappaB), release of NF-kappaB, and transcriptional stimulation of NF-kappaB target genes. Antagonism of this system by viral enzymes that remove ubiquitin and ISG15 from proteins can allow downregulation of both the antiviral and inflammatory responses.
|Active site residues||C40 H151 D153 |
|Active site||Active site residues (see the Alignment) were predicted by analogy with those in the 'OTU' domains (Pfam family PF02338) of several families in clan CA, and confirmed by mutagenesis (Frias-Staheli et al., 2007).|
|Activities and specificities||The peptidases have deubiquitinylase and deISGylase activities (Frias-Staheli et al., 2007).|
|Molecular structure||Family C87 is assigned to clan CA on the basis of the arrangement of active site residues in the sequence.|