PXD033365

PXD033365 is an original dataset announced via ProteomeXchange.

Title	Structural insights into dsRNA processing by Drosophila Dicer-2/Loqs-PD
Description	Small interfering RNAs (siRNAs) are the key components for RNA interference (RNAi), a conserved RNA silencing mechanism in many eukaryotes. In Drosophila, an RNase III enzyme Dicer-2 (Dcr-2), aided by its cofactor Loquacious-PD (Loqs-PD), plays major role in generating 21 base-pair (bp) siRNA duplexes from long double-stranded RNAs (dsRNAs). The ATP hydrolysis by the helicase domain of Dcr-2 is critical to the successful processing of a long dsRNA into consecutive siRNA duplexes. Here we report the cryo-EM structures of Dcr-2/Loqs-PD in the apo state and in multiple processing states of a 50-bp dsRNA substrate. The structures elucidated interactions between Dcr-2 and Loqs-PD, and significant conformational changes of Dcr-2 during a dsRNA processing cycle. The N-terminal helicase and DUF283 domains undergo conformational change upon initial dsRNA binding, forming an ATP binding pocket and a 5’-phosphate binding pocket. The overall conformation of Dcr-2/Loqs-PD is relatively rigid during translocating along the dsRNA in the presence of ATP, while the interaction between DUF283 and RIIIDb domains prevents non-specific cleavage during translocation by blocking the access of dsRNA to the RNase active center. Additional ATP-dependent conformational changes are required to form an active-dicing state and precisely cleave the dsRNA into 21-bp siRNA duplex confirmed by the structure in the post-dicing state. Collectively, this study revealed the molecular mechanism for the full-cycle of ATP-dependent dsRNA processing by Dcr-2/Loqs-PD.
HostingRepository	iProX
AnnounceDate	2022-04-21
AnnouncementXML	Submission_2023-12-25_20:04:55.273.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Chenshi Su
SpeciesList	scientific name: Drosophila melanogaster; NCBI TaxID: 7227;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive

Revision	Datetime	Status	ChangeLog Entry
0	2022-04-21 19:21:32	ID requested
1	2022-04-21 19:21:48	announced
⏵ 2	2023-12-25 20:04:56	announced	2023-12-26: Update information.

submitter keyword: RNAi, siRNA processing, ATP-dependent RNA helicase, Dicer-2, Loqs-PD

Jinbiao Ma
contact affiliation	Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University
contact email	majb@fudan.edu.cn
lab head
Chenshi Su
contact affiliation	Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University
contact email	scsu15@fudan.edu.cn
dataset submitter

iProX dataset URI