>pfam02171 Piwi Piwi domain. 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. 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.

Probab=90.41 E-value=1.5 Score=23.60 Aligned_cols=111 Identities=20% Similarity=0.306 Sum_probs=60.5 Q ss_pred CEEEEEECCCCCCCC----CEEEEEEEECCCCCHHHHHHHHCCCCCCCCCHHHHHHHHHHHHHHHHHHCCCCCCCCCCCC Q ss_conf 169997074437754----0488888516872803232110244445541168998999999997753131112333333 Q gi|255764496|r 380 KRIEIYDNSHIMGCS----AVGCMVVVGENGFVKNQYRKFNLHPNDVKTQDDCAMMRMVLERRFSQLIKNEENLNFHPKK 455 (616) Q Consensus 380 ~rIE~fDiSh~~G~~----~Vas~Vvf~~g~~~K~~YR~f~Ik~~~v~~~DD~~~m~Evi~RR~~r~~~~~~~l~~~~~~ 455 (616) T Consensus 72 tmiiG~DV~h~~~~~~~~~Sv~~~vas~d~~~~-~~~~~~~~q~~~---~e~i~~l~~~~~~~L~~f~~~---------- 137 (296) T pfam02171 72 DVIIGFDVSHPTGGTDDNPSVAGFVASMDKHPQ-KFAGGVRYQASG---QELIESLKDIIKESLRSFYKS---------- 137 (296) T ss_pred CEEEEEEEECCCCCCCCCCEEEEEEEEECCCCC-EEEEEEEEECCC---CCHHHHHHHHHHHHHHHHHHH---------- T ss_conf 359999876799998999649999999569868-786799980799---583876999999999999997---------- Q ss_pred CCCCCCCCCCEEE--EEC-CHHHHHHH--------HHHHHHCCCC--CCCCEEEEECCCCCCCCCEEEECC Q ss_conf 3345457984899--809-85899999--------9999975887--787189997187767663489817 Q gi|255764496|r 456 QEYSFPSWPDVVI--LDG-GKGQLSAA--------QGVLKKLNVE--NRITIISIAKGPKRSAGMEKFFVK 513 (616) Q Consensus 456 ~~~~~~~~PDLil--IDG-GkgQln~a--------~~vl~~l~i~--~~i~viglaK~~~r~~~~e~~~~~ 513 (616) T Consensus 138 ----~~~~P~~IiiyRDGvsegq~~~v~~~Ev~~ik~a~~~~~~~~~pkit~Ivv~Krh~-----~Rff~~ 199 (296) T pfam02171 138 ----RKKKPERIIIYRDGVSEGQFPQVLNYEVNQIKEACKELGEDYNPKLTVIVVQKRHH-----TRFFAS 199 (296) T ss_pred ----CCCCCCEEEEEECCCCCHHHHHHHHHHHHHHHHHHHHHCCCCCCCEEEEEEECCCC-----EEECCC T ss_conf ----08998459999368880458999999999999999985678899789999952432-----143247

HHsearch alignment for GI: 255764496 and conserved domain: pfam02171