| SMART accession number: | SM00670
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| Description: |
From similarities to 5'-exonucleases, these domains are predicted to be RNases. PINc domains in nematode SMG-5 and yeast NMD4p are predicted to be involved in RNAi. |
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| Interpro abstract (IPR006596): |
PINc describes a large group of domains which are predicted to play a role in nucleotide-binding, potentially being found in RNases. PINc domains in nematode SMG-5 and yeast NMD4p are predicted to be involved in the posttranscriptional gene silencing pathway known as RNA interference (RNAi). In an early step in RNAi, the initiating dsRNA is cleaved into small interfering RNAs (siRNAs), 21-23 nucleotides long, by the enzyme Dicer. After processing by Dicer, siRNAs associate with a multicomponent complex called the RNA-induced silencing complex that recognises and cleaves the cognate message [(PUBMED:12419225)].
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| Family alignment: |
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Click on the following links for more information.
- Evolution (species in which this domain is found)
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- Cellular role (predicted cellular role)
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Cellular role: translation
Binding / catalysis: Nucleotides
- Literature (relevant references for this domain)
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Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
- Makarova KS et al.
- Comparative genomics of the Archaea (Euryarchaeota): evolution ofconserved protein families, the stable core, and the variable shell.
- Genome Res. 1999; 9: 608-28
- Display abstract
Comparative analysis of the protein sequences encoded in the foureuryarchaeal species whose genomes have been sequenced completely(Methanococcus jannaschii, Methanobacterium thermoautotrophicum,Archaeoglobus fulgidus, and Pyrococcus horikoshii) revealed 1326orthologous sets, of which 543 are represented in all four species. Theproteins that belong to these conserved euryarchaeal families comprise31%-35% of the gene complement and may be considered the evolutionarilystable core of the archaeal genomes. The core gene set includes the greatmajority of genes coding for proteins involved in genome replication andexpression, but only a relatively small subset of metabolic functions. Formany gene families that are conserved in all euryarchaea, previouslyundetected orthologs in bacteria and eukaryotes were identified. A numberof euryarchaeal synapomorphies (unique shared characters) were identified;these are protein families that possess sequence signatures or domainarchitectures that are conserved in all euryarchaea but are not found inbacteria or eukaryotes. In addition, euryarchaea-specific expansions ofseveral protein and domain families were detected. In terms of theirapparent phylogenetic affinities, the archaeal protein families split intobacterial and eukaryotic families. The majority of the proteins that haveonly eukaryotic orthologs or show the greatest similarity to theireukaryotic counterparts belong to the core set. The families ofeuryarchaeal genes that are conserved in only two or three speciesconstitute a relatively mobile component of the genomes whose evolutionshould have involved multiple events of lineage-specific gene loss andhorizontal gene transfer. Frequently these proteins have detectableorthologs only in bacteria or show the greatest similarity to thebacterial homologs, which might suggest a significant role of horizontalgene transfer from bacteria in the evolution of the euryarchaeota.
- Structure (3D structures containing this domain)
3D Structures of PINc domains in PDB
| PDB code | Main view | Title | | 1o4w |  | Crystal structure of pin (pilt n-terminus) domain (af0591) from archaeoglobus fulgidus at 1.90 a resolution |
| 1w8i |  | The structure of gene product af1683 from archaeoglobus fulgidus. |
| 2dok |  | Crystal structure of the pin domain of human est1a |
| 2hww |  | Structure of pin domain of human smg6 |
| 2hwx |  | Structure of human smg6 e1282c pin domain mutant. |
| 2hwy |  | Structure of pin domain of human smg5. |
| 2wp8 |  | Yeast rrp44 nuclease |
| 3i8o |  | A domain of a functionally unknown protein from methanocaldococcus jannaschii dsm 2661. |
| 3ix7 |  | Crystal structure of a domain of functionally unknown protein from thermus thermophilus hb8 |
- Links (links to other resources describing this domain)
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to expand nodes. To display all proteins with a PINc domain in a specific node, click on it.