Method of producing dicer

A purified, enzymatically active Dicer complex comprising:

• a) a first polypeptide comprising an amino acid sequence having at least 85% sequence identity to:
• (i) amino acids 1-1008 of the amino acid sequence of SEQ ID NO:
• 1 comprising an ATPase/helicase domain, a DUF domain, and a PAZ domain,
• (ii) amino acids 1-1068 of the amino acid sequence of SEQ ID NO:
• 1 comprising an ATPase/helicase domain, a DUF domain, and a PAZ domain,
• (iii) amino acids 605-1008 of the amino acid sequence of SEQ ID NO:
• 1 comprising a DUF and a PAZ domain, or
• (iv) amino acids 605-1068 of the amino acid sequence of SEQ ID NO:
• 1 comprising a DUF and a PAZ domain,
• wherein said first polypeptide lacks an RNase IIIa domain and an RNase IIIb domain;
• and
• b) a second polypeptide comprising an amino acid sequence having at least 85% sequence identity to:
• (i) amino acids 1235 to 1922 of the amino acid sequence of SEQ ID NO:
• 1 comprising an RNaseIIIa domain, an RNaseIIIb domain, and a dsRBD domain,
• (ii) amino acids 1296 to 1922 of the amino acid sequence of SEQ ID NO:1 comprising an RNaseIIIa domain, an RNaseIIIb domain, and dsRBD domain,
• (iii) amino acids 1235 to 1772 of the amino acid sequence of SEQ ID NO:1 comprising an RNaseIIIa and an RNaseIIIb domain, or
• (iv) amino acids 1296 to 1772 of the amino acid sequence of SEQ ID NO:1 comprising an RNaseIIIa and an RNaseIIIb domain,
• wherein said second polypeptide lacks at least one of:
• a DUF domain and a PAZ domain,
• wherein said first polypeptide and said second polypeptide spontaneously associate to form an enzymatically active Dicer complex that has endoribonuclease activity.