Source
Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA. mueller3@niehs.nih.gov.
Abstract
BACKGROUND:
Drosha is a nuclear RNase III enzyme that initiates processing of regulatory microRNA. Together with partner protein DiGeorge syndrome critical region 8 (DGCR8), it forms the Microprocessor complex, which cleaves precursor transcripts called primary microRNA to produce hairpin precursor microRNA. In addition to two RNase III catalytic domains, Drosha contains a C-terminal double-stranded RNA-binding domain (dsRBD). To gain insight into the function of this domain, we determined the nuclear magnetic resonance (NMR) solution structure.
RESULTS:
We report here the solution structure of the dsRBD from Drosha (Drosha-dsRBD). The alphabetabetabetaalpha fold is similar to other dsRBD structures. A unique extended loop distinguishes this domain from other dsRBDs of known structure.
CONCLUSIONS:
Despite uncertainties about RNA-binding properties of the Drosha-dsRBD, its structure suggests it retains RNA-binding features. We propose that this domain may contribute to substrate recognition in the Drosha-DGCR8 Microprocessor complex.