This domain is named PAZ after the proteins Piwi Argonaut and Zwille. This domain is found in two families of proteins that are involved in post-transcriptional gene silencing. These are the Piwi family and the Dicer family, that includes the Carpel ...
This domain is named PAZ after the proteins Piwi Argonaut and Zwille. This domain is found in two families of proteins that are involved in post-transcriptional gene silencing. These are the Piwi family and the Dicer family, that includes the Carpel factory protein. The function of the domains is unknown but has been suggested to mediate complex formation between proteins of the Piwi and Dicer families by hetero-dimerisation. The three-dimensional structure of this domain has been solved [2-4]. The PAZ domain is composed of two subdomains. One subdomain is similar to the OB fold, albeit with a different topology. The OB-fold is well known as a single-stranded nucleic acid binding fold. The second subdomain is composed of a beta-hairpin followed by an alpha-helix. The PAZ domains shows low-affinity nucleic acid binding and appears to interact with the 3' ends of single-stranded regions of RNA in the cleft between the two subdomains. PAZ can bind the characteristic two-base 3' overhangs of siRNAs, indicating that although PAZ may not be a primary nucleic acid binding site in Dicer or RISC, it may contribute to the specific and productive incorporation of siRNAs and miRNAs into the RNAi pathway.
The Prosite family is restricted to DEAD/H helicases, whereas this domain family is found in a wide variety of helicases and helicase related proteins. It may be that this is not an autonomously folding unit, but an integral part of the helicase.
This domain is found in Endoribonuclease Dicer from chordates. This dsRNA endoribonuclease is involved in the cleavage of long RNA precursors into short dsRNAs and plays a role in gene silencing. Dicer shows two N-terminal helicase domains (Pfam:PF04 ...
This domain is found in Endoribonuclease Dicer from chordates. This dsRNA endoribonuclease is involved in the cleavage of long RNA precursors into short dsRNAs and plays a role in gene silencing. Dicer shows two N-terminal helicase domains (Pfam:PF04851 and Pfam:PF00271), a dimerisation domain (Pfam:PF03368), a Platform domain, a PAZ domain (Pfam:PF02170), an RNase IIIa/b domain (Pfam:PF00636) and a dsRNA-binding domain in its C-terminal region (this entry). This domain protrudes from the RNase IIIb domain in the middle of the protein. It may be involved in recruiting RNA substrates [1,2].
This domain is found in Endoribonuclease Dicer from chordates. This dsRNA endoribonuclease is involved in the cleavage of long RNA precursors into short dsRNAs and plays a role in gene silencing. Dicer shows two N-terminal helicase domains (Pfam:PF04 ...
This domain is found in Endoribonuclease Dicer from chordates. This dsRNA endoribonuclease is involved in the cleavage of long RNA precursors into short dsRNAs and plays a role in gene silencing. Dicer shows two N-terminal helicase domains (Pfam:PF04851 and Pfam:PF00271), a dimerisation domain (Pfam:PF03368), a Platform domain, a PAZ domain (Pfam:PF02170), two RNase III a/b domains (Pfam:PF00636) and a dsRNA-binding domain in its C-terminal region. This entry represents the partner-binding domain, which folds into a four-helix bundle. It is is responsible for the interactions with the dsRNA-binding proteins that support the enzymatic activity of Dicer [1,2].
