The domain within your query sequence starts at position 186 and ends at position 251; the E-value for the RNase_PH_C domain shown below is 3.8e-13.



PFAM accession number:PF03725
Interpro abstract (IPR015847):

The PH (phosphorolytic) domain is responsible for 3'-5' exoribonuclease activity, although in some proteins this domain has lost its catalytic function. An active PH domain uses inorganic phosphate as a nucleophile, adding it across the phosphodiester bond between the end two nucleotides in order to release ribonucleoside 5'-diphosphate (rNDP) from the 3' end of the RNA substrate.

PH domains can be found in bacterial/organelle RNases and PNPases (polynucleotide phosphorylases) [ (PUBMED:17084501) ], as well as in archaeal and eukaryotic RNA exosomes [ (PUBMED:15951817) (PUBMED:17174896) ], the later acting as nano-compartments for the degradation or processing of RNA (including mRNA, rRNA, snRNA and snoRNA). Bacterial/organelle PNPases share a common barrel structure with RNA exosomes, consisting of a hexameric ring of PH domains that act as a degradation chamber, and an S1-domain/KH-domain containing cap that binds the RNA substrate (and sometimes accessory proteins) in order to regulate and restrict entry into the degradation chamber [ (PUBMED:16285927) ]. Unstructured RNA substrates feed in through the pore made by the S1 domains, are degraded by the PH domain ring, and exit as nucleotides via the PH pore at the opposite end of the barrel [ (PUBMED:16713559) (PUBMED:17380186) ].

This entry represents the phosphorolytic (PH) domain 2, which has a core 3-layer alpha/beta/alpha structure. This domain is found in bacterial/organelle PNPases and in archaeal/eukaryotic exosomes [ (PUBMED:9390555) ].

This is a PFAM domain. For full annotation and more information, please see the PFAM entry RNase_PH_C