PAZ domain, argonaute_like subfamily. Argonaute is part of the RNA-induced silencing complex (RISC), and is an endonuclease that plays a key role in the RNA interference pathway. The PAZ domain has been named after the proteins Piwi,Argonaut, and Zwille. PAZ is found in two families of proteins that are essential components of RNA-mediated gene-silencing pathways, including RNA interference, the Piwi and Dicer families. PAZ functions as a nucleic acid binding domain, with a strong preference for single-stranded nucleic acids (RNA or DNA) or RNA duplexes with single-stranded 3' overhangs. It has been suggested that the PAZ domain provides a unique mode for the recognition of the two 3'-terminal nucleotides in single-stranded nucleic acids and buries the 3' OH group, and that it might recognize characteristic 3' overhangs in siRNAs within RISC (RNA-induced silencing) and other complexes.