Structural biology is a field that is many centuries old which, as defined by the Journal of Structural Biology, deals with structural analysis of living material at every level of organization. Early structural biologists throughout the 19th and early 20th centuries were primarily only able to study structures to the limit of the naked eye's visual acuity and through magnifying glasses and light microscopes.
Transmission electron cryomicroscopy (CryoTEM), commonly known as cryo-EM, is a form of cryogenic electron microscopy, more specifically a type of transmission electron microscopy (TEM) where the sample is studied at cryogenic temperatures. Cryo-EM, specifically 3-dimensional electron microscopy (3DEM), is gaining popularity in structural biology.
Cryogenic electron tomography (cryoET) is an imaging technique used to reconstruct high-resolution (~1–4 nm) three-dimensional volumes of samples, often biological macromolecules and cells. cryoET is a specialized application of transmission electron cryomicroscopy (CryoTEM) in which samples are imaged as they are tilted, resulting in a series of 2D images that can be combined to produce a 3D reconstruction, similar to a CT scan of the human body. In contrast to other electron tomography techniques, samples are imaged under cryogenic conditions. For cellular material, the structure is immobilized in non-crystalline, vitreous ice, allowing them to be imaged without dehydration or chemical fixation, which would otherwise disrupt or distort biological structures.
Richard Henderson is a British molecular biologist and biophysicist and pioneer in the field of electron microscopy of biological molecules. Henderson shared the Nobel Prize in Chemistry in 2017 with Jacques Dubochet and Joachim Frank."Thanks to his work, we can look at individual atoms of living nature, thanks to cryo-electron microscopes we can see details without destroying samples, and for this he won the Nobel Prize in Chemistry."
The EM Data Bank or Electron Microscopy Data Bank (EMDB) collects 3D EM maps and associated experimental data determined using electron microscopy of biological specimens. It was established in 2002 at the MSD/PDBe group of the European Bioinformatics Institute (EBI), where the European site of the EMDataBank.org consortium is located. As of 2015, the resource contained over 2,600 entries with a mean resolution of 15Å.
Bsoft is a collection of programs and a platform for development of software for image and molecular processing in structural biology. Problems in structural biology are approached with a highly modular design, allowing fast development of new algorithms without the burden of issues such as file I/O. It provides an easily accessible interface, a resource that can be and has been used in other packages. Several workflows such as for single particle analysis and tomography are supported with parameter exchange as well as the ability to do distributed processing across heterogeneous clusters of computers.
Resolution in the context of structural biology is the ability to distinguish the presence or absence of atoms or groups of atoms in a biomolecular structure. Usually, the structure originates from methods such as X-ray crystallography, electron crystallography, or cryo-electron microscopy. The resolution is measured of the "map" of the structure produced from experiment, where an atomic model would then be fit into. Due to their different natures and interactions with matter, in X-ray methods the map produced is of the electron density of the system, whereas in electron methods the map is of the electrostatic potential of the system. In both cases, atomic positions are assumed similarly.
Biology data visualization is a branch of bioinformatics concerned with the application of computer graphics, scientific visualization, and information visualization to different areas of the life sciences. This includes visualization of sequences, genomes, alignments, phylogenies, macromolecular structures, systems biology, microscopy, and magnetic resonance imaging data. Software tools used for visualizing biological data range from simple, standalone programs to complex, integrated systems.
Single particle analysis is a group of related computerized image processing techniques used to analyze images from transmission electron microscopy (TEM). These methods were developed to improve and extend the information obtainable from TEM images of particulate samples, typically proteins or other large biological entities such as viruses. Individual images of stained or unstained particles are very noisy, and so hard to interpret. Combining several digitized images of similar particles together gives an image with stronger and more easily interpretable features. An extension of this technique uses single particle methods to build up a three-dimensional reconstruction of the particle. Using cryo-electron microscopy it has become possible to generate reconstructions with sub-nanometer resolution and near-atomic resolution first in the case of highly symmetric viruses, and now in smaller, asymmetric proteins as well. Single particle analysis can also be performed by induced coupled plasma mass spectroscopy (ICP-MS).
IMOD is an open-source, cross-platform suite of modeling, display and image processing programs used for 3D reconstruction and modeling of microscopy images with a special emphasis on electron microscopy data. IMOD has been used across a range of scales from macromolecule structures to organelles to whole cells and can also be used for optical sections. IMOD includes tools for image reconstruction, image segmentation, 3D mesh modeling and analysis of 2D and 3D data.
Jacques Dubochet is a retired Swiss biophysicist. He is a former researcher at the European Molecular Biology Laboratory in Heidelberg, Germany, and an honorary professor of biophysics at the University of Lausanne in Switzerland.
Cryogenic electron microscopy (cryoEM) is a cryomicroscopy technique applied on samples cooled to cryogenic temperatures. For biological specimens, the structure is preserved by embedding in an environment of vitreous ice. An aqueous sample solution is applied to a grid-mesh and plunge-frozen in liquid ethane or a mixture of liquid ethane and propane. While development of the technique began in the 1970s, recent advances in detector technology and software algorithms have allowed for the determination of biomolecular structures at near-atomic resolution. This has attracted wide attention to the approach as an alternative to X-ray crystallography or NMR spectroscopy for macromolecular structure determination without the need for crystallization.
Lori Anne Passmore is a Canadian/British cryo electron microscopist and structural biologist who works at the Medical Research Council (MRC) Laboratory of Molecular Biology (LMB) at the University of Cambridge. She is known for her work on multiprotein complexes involved in gene expression and development of new supports for cryo-EM.
Sjors Hendrik Willem ScheresFRS is a Dutch scientist at the MRC Laboratory of Molecular Biology Cambridge, UK.
Bridget Olivia Carragher is a South African physicist specialized in electron microscopy.
Microcrystal electron diffraction, or MicroED, is a CryoEM method that was developed by the Gonen laboratory in late 2013 at the Janelia Research Campus of the Howard Hughes Medical Institute. MicroED is a form of electron crystallography where thin 3D crystals are used for structure determination by electron diffraction. Prior to this demonstration, macromolecular (protein) electron crystallography was only used on 2D crystals, for example.
Kiyoshi Nagai was a Japanese structural biologist at the MRC Laboratory of Molecular Biology Cambridge, UK. He was known for his work on the mechanism of RNA splicing and structures of the spliceosome.
Julia Mahamid is a cell biologist, structural biologist, and electron microscopist at the European Molecular Biology Laboratory in Heidelberg, Germany, who utilizes biomolecular condensates and advanced cellular cryo-electron tomography to enhance the comprehension of the functional organization of the cytoplasm. She leads the Mahamid Group.
Tanmay A. M. Bharat is a programme leader in the Structural Studies Division of the MRC Laboratory of Molecular Biology. He and his group use electron tomography, together with several structural and cell biology methods to study the cell surfaces of bacteria and archaea. His work has increased the understanding of how surface molecules help in the formation of multicellular communities of prokaryotes, examples of which include biofilms and microbiomes. He has been awarded several prizes and fellowships for his work.
Gaia Pigino is the Associate Head of the Structural Biology Research Center and Research Group Leader of the Pigino Group at the Human Technopole in Milan, Italy.
