Elucidating the Role of Microprocessor Protein DGCR8 in Bending RNA Structures.

Autor:	Pabit SA; School of Applied and Engineering Physics, Cornell University, Ithaca, New York., Chen YL; School of Applied and Engineering Physics, Cornell University, Ithaca, New York., Usher ET; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania., Cook EC; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania., Pollack L; School of Applied and Engineering Physics, Cornell University, Ithaca, New York. Electronic address: lp26@cornell.edu., Showalter SA; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania. Electronic address: sas76@psu.edu.
Jazyk:	angličtina
Zdroj:	Biophysical journal [Biophys J] 2020 Dec 15; Vol. 119 (12), pp. 2524-2536. Date of Electronic Publication: 2020 Nov 13.
DOI:	10.1016/j.bpj.2020.10.038
Abstrakt:	Although conformational dynamics of RNA molecules are potentially important in microRNA (miRNA) processing, the role of the protein binding partners in facilitating the requisite structural changes is not well understood. In previous work, we and others have demonstrated that nonduplex structural elements and the conformational flexibility they support are necessary for efficient RNA binding and cleavage by the proteins associated with the two major stages of miRNA processing. However, recent studies showed that the protein DGCR8 binds primary miRNA and duplex RNA with similar affinities. Here, we study RNA binding by a small recombinant construct of the DGCR8 protein and the RNA conformation changes that result. This construct, the DGCR8 core, contains two double-stranded RNA-binding domains (dsRBDs) and a C-terminal tail. To assess conformational changes resulting from binding, we applied small-angle x-ray scattering with contrast variation to detect conformational changes of primary-miR-16-1 in complex with the DGCR8 core. This method reports only on the RNA conformation within the complex and suggests that the protein bends the RNA upon binding. Supporting work using smFRET to study the conformation of RNA duplexes bound to the core also shows bending. Together, these studies elucidate the role of DGCR8 in interacting with RNA during the early stages of miRNA processing. (Copyright © 2020 Biophysical Society. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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