Ribonuclease III double-stranded (ds) RNA-specific endoribonuclease that is involved in the initial step of microRNA (miRNA) biogenesis. Component of the microprocessor complex that is required to process primary miRNA transcripts (pri-miRNAs) to release precursor miRNA (pre-miRNA) in the nucleus. Within the microprocessor complex, DROSHA cleaves the 3' and 5' strands of a stem-loop in pri-miRNAs (processing center 11 bp from the dsRNA-ssRNA junction) to release hairpin-shaped pre-miRNAs that are subsequently cut by the cytoplasmic DICER to generate mature miRNAs. Involved also in pre-rRNA processing. Cleaves double-strand RNA and does not cleave single-strand RNA. Involved in the formation of GW bodies. Endonucleolytic cleavage to 5'-phosphomonoester. Each RNase III domain binds at least one Mg(2+) or Mn(2+) ion. Component of the microprocessor complex, or pri-miRNA processing protein complex, which is composed of DROSHA and DGCR8 (PubMed:15589161, PubMed:15574589, PubMed:15531877, PubMed:16751099, PubMed:26027739, PubMed:26748718). The microprocessor complex is a heterotrimer; each of the two DROSHA RNase III domains binds one DGCR8 (via C-terminal region) (PubMed:26027739, PubMed:26748718). Interacts with SP1 and SNIP1 (PubMed:10976766, PubMed:18632581). Interacts with SRRT/ARS2 (By similarity). Interacts with CPSF3 and ISY1; this interaction is in an RNA dependent manner (By similarity). Interacts with PUS10; interaction promotes pri-miRNAs processing (PubMed:31819270). A fraction is translocated to the nucleolus during the S phase of the cell cycle. Localized in GW bodies (GWBs), also known as P-bodies. Ubiquitous. The 2 RNase III domains form an intramolecular dimer where the domain 1 cuts the 3'strand while the domain 2 cleaves the 5'strand of pri-miRNAs, independently of each other. Belongs to the ribonuclease III family. Truncated N-terminus. The dark side of RNA - Issue 87 of October 2007