 Piwi | |
|---|---|
| SMART ACC: | SM000950 |
| Description: | This domain is found in the protein Piwi and its relatives. The function of this domain is the dsRNA guided hydrolysis of ssRNA. Determination of the crystal structure of Argonaute reveals that PIWI is an RNase H domain, and identifies Argonaute as Slicer, the enzyme that cleaves mRNA in the RNAi RISC complex (PUBMED:15284453) . In addition, Mg+2 dependence and production of 3'-OH and 5' phosphate products are shared characteristics of RNaseH and RISC. The PIWI domain core has a tertiary structure belonging to the RNase H family of enzymes. RNase H fold proteins all have a five-stranded mixed beta-sheet surrounded by helices. By analogy to RNase H enzymes which cleave single-stranded RNA guided by the DNA strand in an RNA/DNA hybrid, the PIWI domain can be inferred to cleave single-stranded RNA, for example mRNA, guided by double stranded siRNA. |
| InterPro ACC: | IPR003165 |
| InterPro abstract: | The piwi domain [ PUBMED:11050429 ] is a protein domain found in piwi proteins and a large number of related nucleic acid-binding proteins, especially those that bind and cleave RNA. The function of the domain is double stranded-RNA-guided hydrolysis of single stranded-RNA, as has been determined in the argonaute family … expand |
| GO function: | nucleic acid binding (GO:0003676) |
| Family alignment: | View the Family alignment or the Alignment consensus sequence |
| There are 10 581 Piwi domains in 10 533 proteins in SMART's NRDB database. | |
Taxonomic distribution of proteins containing Piwi domains
The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing Piwi domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.
Predicted cellular role
| Cellular role: | Transcription |
|---|
Relevant references for this domain
Primary literature for the Piwi domain is listed below. Automatically-derived, secondary literature is also available.
KEGG pathways involving proteins which contain this domain
This information is based on the mapping of SMART genomic protein database to KEGG orthologous groups. Percentages are related to the number of proteins containing a Piwi domain which could be assigned to a KEGG orthologous group, and not all proteins containing Piwi domains. Please note that proteins can be included in multiple pathways, ie. the numbers below will not add to 100%.