RNA three-dimensional structures provide rich and vital information for understanding their functions. Recent advances in cryogenic electron microscopy (cryo-EM) allow structure determination of RNAs and ribonucleoprotein (RNP) complexes. However, limited global and local resolutions of RNA cryo-EM maps pose great challenges in tracing RNA coordinates. The Rosetta-based "auto-DRRAFTER" method builds RNA models into moderate-resolution RNA cryo-EM density as part of the Ribosolve pipeline. Here, we describe a step-by-step protocol for auto-DRRAFTER using a glycine riboswitch from Fusobacterium nucleatum as an example. Successful implementation of this protocol allows automated RNA modeling into RNA cryo-EM density, accelerating our understanding of RNA structure-function relationships. Input and output files are being made available at https://github.com/auto-DRRAFTER/springer-chapter .
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/978-1-0716-2687-0_13 | DOI Listing |
J Chem Theory Comput
January 2025
Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, U.K.
Mechanisms of anion permeation within ion channels and nanopores remain poorly understood. Recent cryo-electron microscopy structures of the human bestrophin 1 Cl channel (hBest1) provide an opportunity to evaluate ion interactions predicted by molecular dynamics (MD) simulations against experimental observations. Here, we implement the fully polarizable force field AMOEBA in MD simulations on different conformations of hBest1.
View Article and Find Full Text PDFBiochemistry
December 2024
Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States.
Amyloid diseases feature pathologic deposition of normally soluble proteins and peptides as insoluble fibrils in vital organs. Amyloid fibrils co-deposit with various nonfibrillar components including heparan sulfate (HS), a glycosaminoglycan that promotes amyloid formation in vitro for many unrelated proteins. HS-amyloid interactions have been proposed as a therapeutic target for inflammation-linked amyloidosis wherein N-terminal fragments of serum amyloid A (SAA) protein deposit in the kidney and liver.
View Article and Find Full Text PDFBioinform Adv
November 2024
Department of Computer Science, Old Dominion University, Norfolk, VA 23529, United States.
Summary: Although multiple neural networks have been proposed for detecting secondary structures from medium-resolution (5-10 Å) cryo-electron microscopy (cryo-EM) maps, the loss functions used in the existing deep learning networks are primarily based on cross-entropy loss, which is known to be sensitive to class imbalances. We investigated five loss functions: cross-entropy, Focal loss, Dice loss, and two combined loss functions. Using a U-Net architecture in our DeepSSETracer method and a dataset composed of 1355 box-cropped atomic-structure/density-map pairs, we found that a newly designed loss function that combines Focal loss and Dice loss provides the best overall detection accuracy for secondary structures.
View Article and Find Full Text PDFmBio
November 2024
Department of Microbiology, Immunology & Molecular Genetics, University of California Los Angeles, Los Angeles, California, USA.
Many protein-protein interactions behave differently in biochemically purified forms as compared to their states. As such, determining native protein structures may elucidate structural states previously unknown for even well-characterized proteins. Here, we apply the bottom-up structural proteomics method, , toward a model methanogenic archaeon.
View Article and Find Full Text PDFNat Commun
November 2024
MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
APC/C is a multi-subunit complex that functions as a master regulator of cell division. It controls progression through the cell cycle by timely marking mitotic cyclins and other cell cycle regulatory proteins for degradation. The APC/C itself is regulated by the sequential action of its coactivator subunits CDC20 and CDH1, post-translational modifications, and its inhibitory binding partners EMI1 and the mitotic checkpoint complex.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!