Journal of Structural Biology: X最新文献

{"title":"Eliminating the missing cone challenge through innovative approaches","authors":"Cody Gillman ,&nbsp;Guanhong Bu ,&nbsp;Emma Danelius ,&nbsp;Johan Hattne ,&nbsp;Brent L. Nannenga ,&nbsp;Tamir Gonen","doi":"10.1016/j.yjsbx.2024.100102","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2024.100102","url":null,"abstract":"<div><p>Microcrystal electron diffraction (MicroED) has emerged as a powerful technique for unraveling molecular structures from microcrystals too small for X-ray diffraction. However, a significant hurdle arises with plate-like crystals that consistently orient themselves flat on the electron microscopy grid. If the normal of the plate correlates with the axes of the crystal lattice, the crystal orientations accessible for measurement are restricted because the crystal cannot be arbitrarily rotated. This limits the information that can be acquired, resulting in a missing cone of information. We recently introduced a novel crystallization strategy called suspended drop crystallization and proposed that crystals in a suspended drop could effectively address the challenge of preferred crystal orientation. Here we demonstrate the success of the suspended drop approach in eliminating the missing cone in two samples that crystallize as thin plates: bovine liver catalase and the SARS‑CoV‑2 main protease (Mpro). This innovative solution proves indispensable for crystals exhibiting systematic preferred orientations, unlocking new possibilities for structure determination by MicroED.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100102"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000072/pdfft?md5=7540527cb3411fb26f5be3a6bf21bfcd&pid=1-s2.0-S2590152424000072-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141290118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The parabasal filaments of Trichomonas vaginalis: A new filament and observations using 0.8 nm-resolution scanning electron microscopy","authors":"Sharmila Fiama das Neves Ortiz ,&nbsp;Raphael Verdan ,&nbsp;Gustavo Miranda Rocha ,&nbsp;Kildare Miranda ,&nbsp;Marlene Benchimol","doi":"10.1016/j.yjsbx.2024.100099","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2024.100099","url":null,"abstract":"<div><p><em>Trichomonas vaginalis</em> is the etiologic agent of trichomoniasis, the most common nonviral sexually transmitted infection worldwide, with an estimated 260 million new cases annually. <em>T. vaginalis</em> contains organelles common to all eukaryotic cells, uncommon cell structures such as hydrogenosomes, and a complex and elaborate cytoskeleton constituting the mastigont system. The mastigont system is mainly formed by several proteinaceous structures associated with basal bodies, the pelta-axostylar complex made of microtubules, and striated filaments named the costa and the parabasal filaments (PFs). Although the structural organization of trichomonad cytoskeletons has been analyzed using several techniques, observation using a new generation of scanning electron microscopes with a resolution exceeding 1 nm has allowed more detailed visualization of the three-dimensional organization of the mastigont system. In this study, we have investigated the cytoskeleton of <em>T. vaginalis</em> using a diverse range of scanning probe microscopy techniques, which were complemented by electron tomography and Fast-Fourier methods. This multi-modal approach has allowed us to characterize an unknown parabasal filament and reveal the ultrastructure of other striated fibers that have not been published before. Here, we show the differences in origin, striation pattern, size, localization, and additional details of the PFs, thus improving the knowledge of the cell biology of this parasite.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100099"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000047/pdfft?md5=f5be6fd3381454e5b294408c8f1c6d0c&pid=1-s2.0-S2590152424000047-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140051590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing NMR fragment-based drug screening for membrane protein targets","authors":"Geoffrey C. Li ,&nbsp;Manuel A. Castro ,&nbsp;Thilini Ukwaththage,&nbsp;Charles R. Sanders","doi":"10.1016/j.yjsbx.2024.100100","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2024.100100","url":null,"abstract":"<div><p>NMR spectroscopy has played a pivotal role in fragment-based drug discovery by coupling detection of weak ligand-target binding with structural mapping of the binding site. Fragment-based screening by NMR has been successfully applied to many soluble protein targets, but only to a limited number of membrane proteins, despite the fact that many drug targets are membrane proteins. This is partly because of difficulties preparing membrane proteins for NMR—especially human membrane proteins—and because of the inherent complexity associated with solution NMR spectroscopy on membrane protein samples, which require the inclusion of membrane-mimetic agents such as micelles, nanodiscs, or bicelles. Here, we developed a generalizable protocol for fragment-based screening of membrane proteins using NMR. We employed two human membrane protein targets, both in fully protonated detergent micelles: the single-pass C-terminal domain of the amyloid precursor protein, C99, and the tetraspan peripheral myelin protein 22 (PMP22). For both we determined the optimal NMR acquisition parameters, protein concentration, protein-to-micelle ratio, and upper limit to the concentration of D₆-DMSO in screening samples. Furthermore, we conducted preliminary screens of a plate-format molecular fragment mixture library using our optimized conditions and were able to identify hit compounds that selectively bound to the respective target proteins. It is hoped that the approaches presented here will be useful in complementing existing methods for discovering lead compounds that target membrane proteins.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100100"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000059/pdfft?md5=39c55f7648d09ecd7660ace75e9b5e22&pid=1-s2.0-S2590152424000059-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141240760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coordination of bilayer properties by an inward-rectifier K+ channel is a cooperative process driven by protein-lipid interaction","authors":"Evan J. van Aalst ,&nbsp;Maryam Yekefallah ,&nbsp;Roy A. M. van Beekveld ,&nbsp;Eefjan Breukink ,&nbsp;Markus Weingarth ,&nbsp;Benjamin J. Wylie","doi":"10.1016/j.yjsbx.2024.100101","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2024.100101","url":null,"abstract":"<div><p>Physical properties of biological membranes directly or indirectly govern biological processes. Yet, the interplay between membrane and integral membrane proteins is difficult to assess due to reciprocal effects between membrane proteins, individual lipids, and membrane architecture. Using solid-state NMR (SSNMR) we previously showed that KirBac1.1, a bacterial Inward-Rectifier K⁺ channel, nucleates bilayer ordering and microdomain formation through tethering anionic lipids. Conversely, these lipids cooperatively bind cationic residues to activate the channel and initiate K⁺ flux. The mechanistic details governing the relationship between cooperative lipid loading and bilayer ordering are, however, unknown. To investigate, we generated KirBac1.1 samples with different concentrations of ¹³C-lableded phosphatidyl glycerol (PG) lipids and acquired a full suite of SSNMR 1D temperature series experiments using the ordered all-trans (AT) and disordered <em>trans</em>-gauche (TG) acyl conformations as markers of bilayer dynamics. We observed increased AT ordered signal, decreased TG disordered signal, and increased bilayer melting temperature with increased PG concentration. Further, we identified cooperativity between ordering and direct binding of PG lipids, indicating KirBac1.1-driven bilayer ordering and microdomain formation is a classically cooperative Hill-type process driven by and predicated upon direct binding of PG lipids. Our results provide unique mechanistic insight into how proteins and lipids in tandem contribute to supramolecular bilayer heterogeneity in the lipid membrane.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100101"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000060/pdfft?md5=93c4cf2e0eae744a1e20dcd4448f8094&pid=1-s2.0-S2590152424000060-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141240761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peptoid-based macrodiscs of variable lipid composition for structural studies of membrane proteins by oriented-sample solid-state NMR","authors":"Azamat R. Galiakhmetov,&nbsp;Adit A. Shah,&nbsp;Addison Lane,&nbsp;Carolynn M. Davern,&nbsp;Caroline Proulx,&nbsp;Alexander A. Nevzorov","doi":"10.1016/j.yjsbx.2023.100095","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2023.100095","url":null,"abstract":"<div><p>Solid-state Nuclear Magnetic Resonance (NMR) in combination with magnetically aligned discoidal lipid mimics allows for studying the conformations of membrane proteins in planar, lipid-rich bilayer environments and at the physiological temperature. We have recently demonstrated the general applicability of macrodiscs composed of DMPC lipids and peptoid belts, which yield magnetic alignment and NMR spectroscopic resolution comparable or superior to detergent-containing bicelles. Here we report on a considerable improvement in the magnetic alignment and NMR resolution of peptoid-based macrodiscs consisting of a mixture of the zwitterionic and negatively charged lipids (DMPC/DMPG at the 85% to 15% molar ratio). The resulting linewidths are about 30% sharper due to the higher orientational order parameter likely arising from the stabilizing electrostatic repulsion between the discs. Moreover, highly aligned, detergent-free macrodiscs can be formed with a longer-chain lipid, DPPC. Interestingly, the spectra of Pf1 in the two lipid mimetics are almost indistinguishable, which would mean that the overall transmembrane helix tilt might be governed not only by the hydrophobic matching but also possibly by the interactions of the flanking lysine and arginine residues at the membrane interface.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100095"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152423000119/pdfft?md5=facf5798311ccfe84d39976a2b84f0fc&pid=1-s2.0-S2590152423000119-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138549264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magic-angle spinning NMR structure of Opa60 in lipid bilayers","authors":"Marcel C. Forster,&nbsp;Kumar Tekwani Movellan,&nbsp;Eszter E. Najbauer,&nbsp;Stefan Becker,&nbsp;Loren B. Andreas","doi":"10.1016/j.yjsbx.2024.100098","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2024.100098","url":null,"abstract":"<div><p>Here we report the structure of Opa60 in lipid bilayers using proton-detected magic-angle spinning nuclear magnetic resonance (MAS NMR). Preparations including near-native oligosaccharide lipids reveal a consistent picture of a stable transmembrane beta barrel with a minor increase in the structured region as compared with the previously reported detergent structure. The large variable loops known to interact with host proteins could not be detected, confirming their dynamic nature even in a lipid bilayer environment. The structure provides a starting point for investigation of the functional role of Opa60 in gonococcal infection, which is understood to involve interaction with host proteins. At the same time, it demonstrates the recent advances in proton-detected methodology for membrane protein structure determination at atomic resolution by MAS NMR.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100098"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000035/pdfft?md5=bcfa30af962cd69ec03183b9f0718283&pid=1-s2.0-S2590152424000035-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140015902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure of biomimetic casein micelles: Critical tests of the hydrophobic colloid and multivalent-binding models using recombinant deuterated and phosphorylated β-casein","authors":"Jared K. Raynes ,&nbsp;Jitendra Mata ,&nbsp;Karyn L. Wilde ,&nbsp;John A. Carver ,&nbsp;Sharon M. Kelly ,&nbsp;Carl Holt","doi":"10.1016/j.yjsbx.2024.100096","DOIUrl":"10.1016/j.yjsbx.2024.100096","url":null,"abstract":"<div><p>Milk contains high concentrations of amyloidogenic casein proteins and is supersaturated with respect to crystalline calcium phosphates such as apatite. Nevertheless, the mammary gland normally remains unmineralized and free of amyloid. Unlike κ-casein, β- and α_S-caseins are highly effective mineral chaperones that prevent ectopic and pathological calcification of the mammary gland. Milk invariably contains a mixture of two to five different caseins that act on each other as molecular chaperones. Instead of forming amyloid fibrils, several thousand caseins and hundreds of nanoclusters of amorphous calcium phosphate combine to form fuzzy complexes called casein micelles. To understand the biological functions of the casein micelle its structure needs to be understood better than at present. The location in micelles of the highly amyloidogenic κ-casein is disputed. In traditional hydrophobic colloid models, it, alone, forms a stabilizing surface coat that also determines the average size of the micelles. In the recent multivalent-binding model, κ-casein is present throughout the micelle, in intimate contact with the other caseins. To discriminate between these models, a range of biomimetic micelles was prepared using a fixed concentration of the mineral chaperone β-casein and nanoclusters of calcium phosphate, with variable concentrations of κ-casein. A biomimetic micelle was also prepared using a highly deuterated and <em>in vivo</em> phosphorylated recombinant β-casein with calcium phosphate and unlabelled κ-casein. Neutron and X-ray scattering experiments revealed that κ-casein is distributed throughout the micelle, in quantitative agreement with the multivalent-binding model but contrary to the hydrophobic colloid models.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"9 ","pages":"Article 100096"},"PeriodicalIF":2.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590152424000011/pdfft?md5=e8fc9848e4965cd95d0dfe026d8062cf&pid=1-s2.0-S2590152424000011-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139634123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery, characterization, and redesign of potent antimicrobial thanatin orthologs from Chinavia ubica and Murgantia histrionica targeting E. coli LptA","authors":"Kelly Huynh ,&nbsp;Amanuel Kibrom ,&nbsp;Bruce R. Donald ,&nbsp;Pei Zhou","doi":"10.1016/j.yjsbx.2023.100091","DOIUrl":"https://doi.org/10.1016/j.yjsbx.2023.100091","url":null,"abstract":"<div><p><em>Podisus maculiventris</em> thanatin has been reported as a potent antimicrobial peptide with antibacterial and antifungal activity. Its antibiotic activity has been most thoroughly characterized against <em>E. coli</em> and shown to interfere with multiple pathways, such as the lipopolysaccharide transport (LPT) pathway comprised of seven different Lpt proteins. Thanatin binds to <em>E. coli</em> LptA and LptD, thus disrupting the LPT complex formation and inhibiting cell wall synthesis and microbial growth. Here, we performed a genomic database search to uncover novel thanatin orthologs, characterized their binding to <em>E. coli</em> LptA using bio-layer interferometry, and assessed their antimicrobial activity against <em>E. coli</em>. We found that thanatins from <em>Chinavia ubica</em> and <em>Murgantia histrionica</em> bound tighter (by 3.6- and 2.2-fold respectively) to LptA and exhibited more potent antibiotic activity (by 2.1- and 2.8-fold respectively) than the canonical thanatin from <em>P. maculiventris</em>. We crystallized and determined the LptA-bound complex structures of thanatins from <em>C. ubica</em> (1.90 Å resolution), <em>M. histrionica</em> (1.80 Å resolution), and <em>P. maculiventris</em> (2.43 Å resolution) to better understand their mechanism of action. Our structural analysis revealed that residues A10 and I21 in <em>C. ubica</em> and <em>M. histrionica</em> thanatin are important for improving the binding interface with LptA, thus overall improving the potency of thanatin against <em>E. coli</em>. We also designed a stapled variant of thanatin that removes the need for a disulfide bond but retains the ability to bind LptA and antibiotic activity. Our discovery presents a library of novel thanatin sequences to serve as starting scaffolds for designing more potent antimicrobial therapeutics.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"8 ","pages":"Article 100091"},"PeriodicalIF":2.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49857582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time tracking of drug binding to influenza A M2 reveals a high energy barrier","authors":"Kumar Tekwani Movellan,&nbsp;Melanie Wegstroth,&nbsp;Kerstin Overkamp,&nbsp;Andrei Leonov,&nbsp;Stefan Becker,&nbsp;Loren B. Andreas","doi":"10.1016/j.yjsbx.2023.100090","DOIUrl":"10.1016/j.yjsbx.2023.100090","url":null,"abstract":"<div><p>The drug Rimantadine binds to two different sites in the M2 protein from influenza A, a peripheral site and a pore site that is the primary site of efficacy. It remained enigmatic that pore binding did not occur in certain detergent micelles, and in particular incomplete binding was observed in a mixture of lipids selected to match the viral membrane. Here we show that two effects are responsible, namely changes in the protein upon pore binding that prevented detergent solubilization, and slow binding kinetics in the lipid samples. Using 55–100 kHz magic-angle spinning NMR, we characterize kinetics of drug binding in three different lipid environments: DPhPC, DPhPC with cholesterol and viral mimetic membrane lipid bilayers. Slow pharmacological binding kinetics allowed the characterization of spectral changes associated with non-specific binding to the protein periphery in the kinetically trapped pore-apo state. Resonance assignments were determined from a set of proton-detected 3D spectra. Chemical shift changes associated with functional binding in the pore of M2 were tracked in real time in order to estimate the activation energy. The binding kinetics are affected by pH and the lipid environment and in particular cholesterol. We found that the imidazole-imidazole hydrogen bond at residue histidine 37 is a stable feature of the protein across several lipid compositions. Pore binding breaks the imidazole-imidazole hydrogen bond and limits solubilization in DHPC detergent.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"8 ","pages":"Article 100090"},"PeriodicalIF":2.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10285276/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9772104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryo-EM of a heterogeneous biochemical fraction elucidates multiple protein complexes from a multicellular thermophilic eukaryote","authors":"Dmitry A. Semchonok ,&nbsp;Fotis L. Kyrilis ,&nbsp;Farzad Hamdi ,&nbsp;Panagiotis L. Kastritis","doi":"10.1016/j.yjsbx.2023.100094","DOIUrl":"10.1016/j.yjsbx.2023.100094","url":null,"abstract":"<div><p>Biomolecular complexes and their interactions govern cellular structure and function. Understanding their architecture is a prerequisite for dissecting the cell's inner workings, but their higher-order assembly is often transient and challenging for structural analysis. Here, we performed cryo-EM on a single, highly heterogeneous biochemical fraction derived from <em>Chaetomium thermophilum</em> cell extracts to visualize the biomolecular content of the multicellular eukaryote. After cryo-EM single-particle image processing, results showed that a simultaneous three-dimensional structural characterization of multiple chemically diverse biomacromolecules is feasible. Namely, the thermophilic, eukaryotic complexes of (a) ATP citrate-lyase, (b) Hsp90, (c) 20S proteasome, (d) Hsp60 and (e) UDP-glucose pyrophosphorylase were characterized. In total, all five complexes have been structurally dissected in a thermophilic eukaryote in a total imaged sample area of 190.64 μm², and two, in particular, 20S proteasome and Hsp60, exhibit side-chain resolution features. The <em>C. thermophilum</em> Hsp60 near-atomic model was resolved at 3.46 Å (FSC = 0.143) and shows a hinge-like conformational change of its equatorial domain, highly similar to the one previously shown for its bacterial orthologue, GroEL. This work demonstrates that cryo-EM of cell extracts will greatly accelerate the structural analysis of cellular complexes and provide unprecedented opportunities to annotate architectures of biomolecules in a holistic approach.</p></div>","PeriodicalId":17238,"journal":{"name":"Journal of Structural Biology: X","volume":"8 ","pages":"Article 100094"},"PeriodicalIF":2.9,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10451023/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10107408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}