Cryo-electron microscopy (cryo-EM) is an emerging experimental method to characterize the structure of large biomolecular assemblies. Single particle cryo-EM records 2D images (so-called micrographs) of projections of the three-dimensional particle, which need to be processed to obtain the threedimensional reconstruction. A crucial step in the reconstruction process is particle picking which in...

For many years two techniques have dominated structural biology - X-ray crystallography and NMR spectroscopy. Traditional cryo-electron microscopy of biological macromolecules produced macromolecular reconstructions at resolution limited to 6-10 Å. Recent development of transmission electron microscopes, in particular the development of direct electron detectors, and continuous improvements in ...

To understand the response of the Lyme disease spirochete Borrelia burgdorferi exposed to stress conditions and assess the viability of this spirochete, we used a correlative cryo-fluorescence and cryo-scanning microscopy approach. This approach enables simple exposition of bacteria to various experimental conditions that can be stopped at certain time intervals by cryo-immobilization, examinat...

A growing array of experimental techniques allows us to characterize the three-dimensional structure of large biological assemblies at increasingly higher resolution. In addition to X-ray crystallography and nuclear magnetic resonance in solution, new structure determination methods such cryo-electron microscopy (cryo-EM), crosslinking/mass spectrometry and solid-state NMR have emerged. Often i...

Despite great progress in the identification and characterization of the key molecular players in neuronal function, remarkably little is known about their supramolecular organization. Cryo-electron tomography (cryo-ET), providing three-dimensional views of the molecular components of the cell in their native, fully hydrated environment, is uniquely positioned to elucidate the native architectu...

Cryo-electron microscopy (cryo-EM) has produced density maps of various resolutions. Although α-helices can be detected from density maps at 5-8 Å resolutions, β-strands are challenging to detect at such density maps due to close-spacing of β-strands. The variety of shapes of β-sheets adds the complexity of β-strands detection from density maps. We propose a new approach to model traces of β-st...

Low-dose images obtained by electron cryo-microscopy (cryo-EM) are often affected by blurring caused by sample motion during electron beam exposure, degrading signal especially at high resolution. We show here that we can align frames of movies, recorded with a direct electron detector during beam exposure of rotavirus double-layered particles, thereby greatly reducing image blurring caused by ...

We report here the protocol adopted to build the atomic model of the newly discovered virus FLiP (Flavobacterium infecting, lipid-containing phage) into 3.9 Å cryo-electron microscopy (cryo-EM) maps. In particular, this report discusses the combination of density modification procedures, automatic model building and bioinformatics tools applied to guide the tracing of the major capsid protein (...

Cryo-electron microscopy (cryo-EM) of biological molecules in single-particle (i.e., unordered, nonaggregated) form is a new approach to the study of molecular assemblies, which are often too large and flexible to be amenable to X-ray crystallography. New insights into biological function on the molecular level are expected from cryo-EM applied to the study of such complexes "trapped" at differ...

Methods Women with ESBC were treated 7-10 days preceding mastectomy with either cryo (n=6), single-dose ipi at 10mg/kg (n=6), or cryo+ipi (n=6) [6]. From serial blood (baseline & 1-month post-mastectomy) and tumor (biopsy & mastectomy), fold-changes following cryo+ipi versus monotherapy were compared (Wilcoxon ranksum) across the following measures: Ki67+ or ICOShi T-cells [2] and intratumoral ...