Learning cis-regulatory principles of ADAR-based RNA editing from CRISPR-mediated mutagenesis

Adenosine-to-inosine (A-to-I) RNA editing catalyzed by ADAR enzymes occurs in double-stranded RNAs. Despite a compelling need towards predictive understanding of natural and engineered editing events, how the RNA sequence and structure determine the editing efficiency and specificity (i.e., cis-regulation) is poorly understood. We apply a CRISPR/Cas9-mediated saturation mutagenesis approach to generate libraries of mutations near three natural editing substrates at their endogenous genomic loci. We use machine learning to integrate diverse RNA sequence and structure features to model editing levels measured by deep sequencing. We confirm known features and identify new features important for RNA editing. Training and testing XGBoost algorithm within the same substrate yield models that explain 68 to 86 percent of substrate-specific variation in editing levels. However, the models do not generalize across substrates, suggesting complex and context-dependent regulation patterns. Our integrative approach can be applied to larger scale experiments towards deciphering the RNA editing code.

A Brief of Review: Multimedia Authoring Tool Attributes

Multimedia authoring is the process of assembling various types of media content such as audio, video, text, images, and animation into a multimedia presentation using tools. Multimedia Authoring Tool is a useful tool that helps authors to create multimedia presentations. Multimedia presentations are very widely used in various fields, such as broadcast digital information delivery, digital visual communication in smart cars, and others. The Multimedia Authoring tool attributes are the factors that determine the quality of a multimedia authoring tool. A multimedia authoring tool needs to have several attributes so that these tools can be used properly. The purpose of this literature review study is to find the advantages of the multimedia authoring tool attribute in each of the existing studies to produce knowledge on how to create a good quality multimedia authoring tool. These attributes are Editing, Services, Performance, and the Formal Verification Model. Editing attribute is an attribute for interfacing with the author. Followed by Service attribute and performance attribute to check and achieve proper multimedia documents. Since 1998, a multimedia modeling tool has been studied, and up to now, there have been many studies that have focused on one or more of these attributes. This article discusses the existing studies to examine the attributes generated from the studies. Multimedia authoring attributes are very important to study because they are the benchmarks of the software requirement specifications of Multimedia Authoring tools. The use of the Petri net model, the Hoare Logic, and the Simple Interactive Multimedia Model as a formal verification model can improve the performance of the Multimedia Authoring Tool. In the questionnaire that was submitted to the users, it was assessed positively by the users with the improvements in the Multimedia Authoring Tool.

Maintaining Semantic Information across Generic 3D Model Editing Operations

Many of today’s data models for 3D applications, such as City Geography Markup Language (CityGML) or Industry Foundation Classes (IFC) encode rich semantic information in addition to the traditional geometry and materials representation. However, 3D editing techniques fall short of maintaining the semantic information across edit operations if they are not tailored to a specific data model. While semantic information is often lost during edit operations, geometry, UV mappings, and materials are usually maintained. This article presents a data model synchronization method that preserves semantic information across editing operation relying only on geometry, UV mappings, and materials. This enables easy integration of existing and future 3D editing techniques with rich data models. The method links the original data model to the edited geometry using point set registration, recovering the existing information based on spatial and UV search methods, and automatically labels the newly created geometry. An implementation of a Level of Detail 3 (LoD3) building editor for the Virtual Singapore project, based on interactive push-pull and procedural generation of façades, verified the method with 30 common editing tasks. The implementation synchronized changes in the 3D geometry with a CityGML data model and was applied to more than 100 test buildings.

Ensembles generated from crystal structures of single distant homologues solve challenging molecular-replacement cases inAMPLE

Molecular replacement (MR) is the predominant route to solution of the phase problem in macromolecular crystallography. Although routine in many cases, it becomes more effortful and often impossible when the available experimental structures typically used as search models are only distantly homologous to the target. Nevertheless, with current powerful MR software, relatively small core structures shared between the target and known structure, of 20–40% of the overall structure for example, can succeed as search models where they can be isolated. Manual sculpting of such small structural cores is rarely attempted and is dependent on the crystallographer's expertise and understanding of the protein family in question. Automated search-model editing has previously been performed on the basis of sequence alignment, in order to eliminate, for example, side chains or loops that are not present in the target, or on the basis of structural features (e.g.solvent accessibility) or crystallographic parameters (e.g.Bfactors). Here, based on recent work demonstrating a correlation between evolutionary conservation and protein rigidity/packing, novel automated ways to derive edited search models from a given distant homologue over a range of sizes are presented. A variety of structure-based metrics, many readily obtained from online webservers, can be fed to the MR pipelineAMPLEto produce search models that succeed with a set of test cases where expertly manually edited comparators, further processed in diverse ways withMrBUMP, fail. Further significant performance gains result when the structure-based distance geometry methodCONCOORDis used to generate ensembles from the distant homologue. To our knowledge, this is the first such approach whereby a single structure is meaningfully transformed into an ensemble for the purposes of MR. Additional cases further demonstrate the advantages of the approach.CONCOORDis freely available and computationally inexpensive, so these novel methods offer readily available new routes to solve difficult MR cases.