Dicer is a multi-domain protein with a complex structure that includes RNase III domains, a PAZ domain, a helicase domain, and a dsRNA-binding domain. The RNase III domains are responsible for the catalytic activity, cleaving the dsRNA into smaller fragments. The PAZ domain binds to the ends of dsRNA, positioning it correctly for cleavage. The helicase domain may assist in unwinding RNA structures, and the dsRNA-binding domain stabilizes the interaction with dsRNA.
