>TIGR02065 ECX1 exosome complex exonuclease 1; InterPro: IPR011807 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) , as well as in archaeal and eukaryotic RNA exosomes , , 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 . 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 , . This entry represents a family of archaeal proteins that are orthologous to the eukaryotic exosome protein Rrp41. It is somewhat more distantly related to the bacterial protein ribonuclease PH. An exosome-like complex has been demonstrated experimentally for the Archaea in Sulfolobus solfataricus, so members of this family are designated exosome complex exonuclease 1, after usage in SwissProt .; GO: 0016896 exoribonuclease activity producing 5'-phosphomonoesters, 0000178 exosome (RNase complex).

Probab=100.00 E-value=5.6e-45 Score=384.55 Aligned_cols=225 Identities=29% Similarity=0.465 Sum_probs=202.2 Q ss_pred HHHCCCCCCCCCCCCCEEEEEEEECCCCCCCCEEEEEECCCEEEEEEEECCCCCCCCCCCCCCCCEEEEEEEECCCCCCC Q ss_conf 98728866588677533787998447546670089998797689999816865212233445442035877405887544 Q gi|254780784|r 306 VMLDKKVRMDGRDSETVRDISAQVGLLQRTHGSSLFIRGDTQAIVVVTLGTREDEQYVDSLSGTQRNDFMMHYNFLPCAT 385 (699) Q Consensus 306 ~ILeeg~R~DGR~~dEIRpIs~EvgvLPrvHGSALFtRGETQaL~tvTLG~~~d~Q~iD~l~~~~~k~fmlHYNFPpfsv 385 (699) T Consensus 2 l~~~dg~R~DGR~pdeLRp~KI~~GvL~rADGSA~~E~G~tki~aAVY-GPrE~hpRh~~~PDRAV~R--~RY~MAPFSv 78 (231) T TIGR02065 2 LILEDGLRLDGRKPDELRPVKIEAGVLKRADGSAYLEFGATKIVAAVY-GPREAHPRHLQLPDRAVLR--VRYNMAPFSV 78 (231) T ss_pred CCCCCCCCCCCCCCCCCCCEEEEEECCCCCCCHHHHCCCCCEEEEEEE-CCCCCCCCCCCCCCCEEEE--EEECCCCCCC T ss_conf 567888545877842012010013111127600101137979999863-7766777545788835776--0013898874 Q ss_pred -CCCCCCCCCCCHHHHHHHHHHHHHHHCCCCCCCCCEEEEEEEEECCCCCCCHHHHHHHHHHHHHHCCCCCCCCCCEEEE Q ss_conf -5334556765024679999999874107864468738999853110278522356677779876259502254121332 Q gi|254780784|r 386 -GEVSRMGAPSRREIGHGRLARRAIHPVLPQTAQFPYTLRIVSEITESDGSSSMATVCGSSLALMDAGVPISKPVAGIAM 464 (699) Q Consensus 386 -GE~~~~~~~~RREiGHg~la~ral~~~~P~~~~~p~tirv~~evl~sngsssma~vc~~slal~dagvp~~~~VaGiam 464 (699) T Consensus 79 kDERK-~PgPdRR~iEiSKv~~EALepai~~E~fPRt~IDVF~EvLQADaGTR~AgltAASlALADAGIpMRDLV~gvav 157 (231) T TIGR02065 79 KDERK-RPGPDRREIEISKVIREALEPAILLEQFPRTAIDVFVEVLQADAGTRCAGLTAASLALADAGIPMRDLVVGVAV 157 (231) T ss_pred CCCCC-CCCCCCCEEHHHHHHHHHCCCEEEEECCCCCCCEEEEEEEECCCCHHHHHHHHHHHHHHHCCCHHHHHHHEEEE T ss_conf 34678-72229441215668888513101322388950105789985276504788999999998479402422000034 Q ss_pred EEEEECCEEEEEEECCCCCCCCCCCCEEEEEC--CCCCEEEECCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHCCCC Q ss_conf 00440882899863144220136551001005--565124432453655688999999999999999999999843566 Q gi|254780784|r 465 GLVKDGDDFIILSDISGDEDHLGHMDFKVAGT--DSGITAMQMDMKIGGISENIMVMALQQAKRGRLHILNEMSKVLSE 541 (699) Q Consensus 465 GLi~~~~~~~iLtDI~G~ED~~GdMDFKvaGT--~~GiTa~QmDiK~~gi~~~il~~al~~A~~gr~~il~~m~~~~~~ 541 (699) T Consensus 158 GKv---~G~vVL-Dl~~~ED~yGEAD~P~A~mP~~~~iTLLQld---G~~T~dEF~~A~~lA~~g~~~v~~~~r~ALk~ 229 (231) T TIGR02065 158 GKV---DGVVVL-DLSELEDMYGEADVPLAIMPKLGEITLLQLD---GDLTPDEFRQALDLAVKGIKRVYEIQREALKK 229 (231) T ss_pred EEE---CCEEEE-CCCCCCCCCCCCCCHHHHCCCCCCEEEEEEC---CCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHC T ss_conf 556---788898-3661246757656566515899826899747---98686789999999999988999999998640

HHsearch alignment for GI: 254780784 and conserved domain: TIGR02065