SEARCH · Engineering Papers

Results for “cryoEM”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

22 records · Page 2

All sources NASA NTRS DOE OSTI

DOE OSTI2026

Human NLRP3 inflammasome activation leads to formation of condensate at the microtubule organizing center

The NLRP3 inflammasome is a multiprotein molecular machine that drives inflammatory responses in innate immunity. Although its dysregulation is implicated in numerous human diseases, its structural organization in cells remains poorly understood. Here, we used precise fluorescence-guided cryo–focused ion beam (cryo-FIB) milling and cryo–electron tomography (cryo-ET) to visualize NLRP3 inflammasomes in situ within human macrophages at various stages of activation. After priming and activation, we observed expansion and dispersion of Golgi cisternae, along with the emergence of 50-nanometer NLRP3-associated vesicles, which likely transport NLRP3 to the MTOC. Dense NLRP3-containing condensates then formed in and around the MTOC. In later stages, the condensates solidified, coincident with widespread mitochondrial damage, autophagy, and pyroptotic cell death.

Wang, Jue [Division of Chemistry and Chemical Engi↗

DOE OSTI2025

Combining MicroED and native mass spectrometry for structural discovery of enzyme–small molecule complexes

With the goal of accelerating the discovery of small molecule–protein complexes, we leverage fast, low-dose, event-based electron counting microcrystal electron diffraction (MicroED) data collection and native mass spectrometry. This approach, which we term electron diffraction with native mass spectrometry (ED-MS), allows assignment of protein target structures bound to ligands with data obtained from crystal slurries soaked with mixtures of known inhibitors and crude biosynthetic reactions. This extends to libraries of printed ligands dispensed directly onto TEM grids for later soaking with microcrystal slurries, and complexes with noncovalent ligands. ED-MS resolves structures of the natural product, epoxide-based cysteine protease inhibitor E-64, and its biosynthetic analogs bound to the model cysteine protease, papain. It further identifies papain binding to its preferred natural products, by showing that two analogs of E-64 outcompete others in binding to papain crystals, and by detecting papain bound to E-64 and an analog from crude biosynthetic reactions, without purification. ED-MS also resolves binding of the CTX-M-14 β-lactamase, a target of active drug development, to the non-β-lactam inhibitor, avibactam, alone or in a cocktail of unrelated compounds. These results illustrate the utility of ED-MS for natural product ligand discovery and for structure-based screening of small molecule binders to macromolecular targets, promising utility for drug discovery.

MicroED↗

DOE OSTI2026

Cryo-electron microscopy structure of a zinc uptake ABC transporter

Zn2+ is an essential micronutrient required for many biological processes. Microorganisms employ high-affinity Zn2+ ABC transporters to take up zinc from the environment when it is scarce, yet the mechanism of zinc uptake and its regulation remain poorly understood. Here, we report the cryo-electron microscopy structure of the Zn2+ ABC transporter complex ZnuB-ZnuC from Escherichia coli. It contains two ZnuB transport and two ZnuC regulatory subunits. The ZnuB homodimer is in an outward-facing, closed conformation with a large hydrophilic cavity at the dimer interface. Each ZnuC subunit contains an N-terminal nucleotide-binding domain and a C-terminal zinc-sensing domain (ZSD). Zn2+ binding to the ZSD locks the transporter in a closed state, whereas under low-Zn2+ conditions, the disorder of ZSD permits ATP-driven zinc uptake. Zn2+ ABC transporters are ubiquitously utilized by pathogenic bacteria to compete with hosts for Zn2+. These findings reveal potential therapeutic targets for disrupting Zn2+ homeostasis in antibiotic-resistant pathogens.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2025

Cyanobacteria and Chloroflexota cooperate to structure light-responsive biofilms

Microbial mats are stratified communities often dominated by unicellular and filamentous phototrophs within an exopolymer matrix. It is challenging to quantify the dynamic responses of community members in situ as they experience steep gradients and rapid fluctuations of light. To address this, we developed a binary consortium using two representative isolates from hot spring mats: the unicellular oxygenic phototrophic cyanobacterium Synechococcus OS-B′ (Syn OS-B′) and the filamentous anoxygenic phototroph Chloroflexus MS-CIW-1 (Chfl MS-1). We quantified the motility of individual cells and entire colonies and demonstrated that Chfl MS-1 formed bundles of filaments that moved in all directions with no directional bias to light. Syn OS-B′ was slightly less motile but exhibited positive phototaxis. This binary consortium displayed cooperative behavior by moving further than either species alone and formed ordered arrays where both species aligned with the light source. No cooperative motility was observed when a nonmotile pilB mutant of Syn OS-B′ was used instead of Syn OS-B′. The binary consortium also produced more adherent biofilm than individual species, consistent with the close interspecies association revealed by electron microscopy. We propose that cyanobacteria and Chloroflexota cooperate in forming natural microbial mats by colonizing new niches and building robust biofilms.

Functional and Systems Biology↗