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Full-Text Articles in Physical Sciences and Mathematics

Structural Evidence For Consecutive Hel308-Like Modules In The Spliceosomal Atpase Brr2, L. Zhang, T. Xu, Corina Maeder, L.-O. Bud, J. Shanks, J. Nix, C. Guthrie, J. A. Pleiss, R. Zhao May 2019

Structural Evidence For Consecutive Hel308-Like Modules In The Spliceosomal Atpase Brr2, L. Zhang, T. Xu, Corina Maeder, L.-O. Bud, J. Shanks, J. Nix, C. Guthrie, J. A. Pleiss, R. Zhao

Corina Maeder

Brr2 is a DExD/H-box helicase responsible for U4/U6 unwinding during spliceosomal activation. Brr2 contains two helicase-like domains, each of which is followed by a Sec63 domain with unknown function. We determined the crystal structure of the second Sec63 domain, which unexpectedly resembles domains 4 and 5 of DNA helicase Hel308. This, together with sequence similarities between Brr2's helicase-like domains and domains 1-3 of Hel308, led us to hypothesize that Brr2 contains two consecutive Hel308-like modules (Hel308-I and Hel308-II). Our structural model and mutagenesis data suggest that Brr2 shares a similar helicase mechanism with Hel308. We demonstrate that Hel308-II interacts with …


Conformational Dynamics Of Single Pre-Mrna Molecules During In Vitro Splicing, J. Abelson, M. Blanco, M. A. Ditzler, F. Fuller, P. Aravamudhan, M. Wood, T. Villa, D. E. Ryan, J. A. Pleiss, Corina Maeder, C. Guthrie May 2019

Conformational Dynamics Of Single Pre-Mrna Molecules During In Vitro Splicing, J. Abelson, M. Blanco, M. A. Ditzler, F. Fuller, P. Aravamudhan, M. Wood, T. Villa, D. E. Ryan, J. A. Pleiss, Corina Maeder, C. Guthrie

Corina Maeder

The spliceosome is a complex small nuclear RNA (snRNA)-protein machine that removes introns from pre-mRNAs via two successive phosphoryl transfer reactions. The chemical steps are isoenergetic, yet splicing requires at least eight RNA-dependent ATPases responsible for substantial conformational rearrangements. To comprehensively monitor pre-mRNA conformational dynamics, we developed a strategy for single-molecule FRET (smFRET) that uses a small, efficiently spliced yeast pre-mRNA, Ubc4, in which donor and acceptor fluorophores are placed in the exons adjacent to the 5′ and 3′ splice sites. During splicing in vitro, we observed a multitude of generally reversible time-and ATP-dependent conformational transitions of individual pre-mRNAs. The …


Factors Affecting The Association Of Single- And Double-Stranded Rnas With Montmorillonite Nanoclays, A. Gujjari, B. V. Rodriguez, J. Pescador, Corina Maeder, G. W. Beall, L. K. Lewis May 2019

Factors Affecting The Association Of Single- And Double-Stranded Rnas With Montmorillonite Nanoclays, A. Gujjari, B. V. Rodriguez, J. Pescador, Corina Maeder, G. W. Beall, L. K. Lewis

Corina Maeder

Montmorillonite (MMT) nanoclays exist as single and stacked sheet-like structures with large surface areas that can form stable associations with many naturally occurring biomolecules, including nucleic acids. They have been utilized successfully as vehicles for delivery of both drugs and genes into cells. Most previous studies have focused on interactions of MMT with DNA. In the current study, we have investigated the binding of small RNAs similar to those used for RNA interference (RNAi) therapy to two major forms of the clay, Na-MMT and Ca-MMT. Association of both forms of MMT with several double-stranded RNAs (dsRNAs), including 25mers, 54mers and …