Biology subjects

Sharov, G.

Publications and source records attributed to Sharov, G..

4 recordsLinked to original sources

bioRxiv2024

EMhub: a web platform for data management and on-the-fly processing in scientific facilities

Most scientific facilities produce large amounts of heterogeneous data at a rapid pace. Managing users, instruments, reports, and invoices presents additional challenges. To address these challenges, we introduce EMhub, a web platform designed to support the daily operations and record-keeping of a scientific facility. EMhub enables easy management of user information, instruments, bookings, and projects. The application was initially developed to meet the needs of a CryoEM facility, but its functionality and adaptability have proven broad enough to be extended to other data-generating centers. The expansion of EMHub is enabled by the modular nature of its core functionalities. The application allows external processes to be connected via a REST API, automating tasks such as folder creation, user and password generation, and execution of real-time data processing pipelines. EMhub has been used for several years at the Swedish National CryoEM Facility and installed in the CryoEM center at the Structural Biology Department at St. Jude Childrens Research Hospital. A fully automated single-particle pipeline has been implemented for on-the-fly data processing and analysis. At St. Jude, the X-Ray Crystallography Center and the Single-Molecule Imaging Center have already expanded the platform to support their operational and data management workflows.

biophysics↗

bioRxiv2022

Cytomotive actins and tubulins share a polymerisation switch mechanism conferring robust dynamics

Protein filaments are used in myriads of ways to organise other molecules in space and time within cells. Some filament-forming proteins couple the hydrolysis of nucleotides to their polymerisation cycle, thus powering the directed movement of other molecules. These filaments are termed cytomotive. Only members of the actin and tubulin protein superfamilies are known to form cytomotive filaments. We sought to examine the basis of cytomotivity via structural studies of the polymerisation cycles of actin and tubulin homologues from across the tree of life. We analysed published data and performed new structural experiments designed to disentangle functional components of these complex filament systems. In sum, our analysis demonstrates the existence of shared subunit polymerisation switches amongst both cytomotive actins and tubulins, i.e. the conformation of subunits switches upon assembly into filaments. Such cytomotive switches explain filament robustness, by enabling the coupling of kinetic and structural polarities required for useful cytomotive behaviours, and by ensuring that single cytomotive filaments do not fall apart.

molecular biology↗

bioRxiv2021

New tools for automated cryo-EM single-particle analysis in RELION-4.0

1We describe new tools for the processing of electron cryo-microscopy (cryo-EM) images in the fourth major release of the RELION software. In particular, we introduce VDAM, a Variable-metric gradient Descent algorithm with Adaptive Moments estimation, for image refinement; a convolutional neural network for unsupervised selection of 2D classes; and a flexible framework for the design and execution of multiple jobs in pre-defined workflows. In addition, we present a stand-alone utility called MDCatch that links the execution of jobs within this framework with metadata gathering during microscope data acquisition. The new tools are aimed at providing fast and robust procedures for unsupervised cryo-EM structure determination, with potential applications for on-the-fly processing and the development of flexible, high-throughput structure determination pipelines. We illustrate their potential on twelve publicly available cryo-EM data sets.

biophysics↗

bioRxiv2020

Using Relion software within Scipion framework

Scipion is a modular image processing framework integrating several software packages under a unified interface while taking care of file formats and conversions. Here new developments and capabilities of the Scipion plugin for the Relion software are presented and illustrated with the image processing pipeline of published data. The user interfaces of Scipion and Relion are compared and the key differences highlighted, allowing this manuscript to be used as a guide for both new and experienced users of these software. Different streaming image processing options are also discussed demonstrating the flexibility of the Scipion framework. SynopsisAn overview of the Scipion plugin for the Relion software is presented and various capabilities of image processing within Scipion framework are discussed.

biophysics↗