StructurePub Date : 2024-11-29DOI: 10.1016/j.str.2024.11.004
Elnaz Khalili Samani, S.M. Naimul Hasan, Matthew Waas, Alexander F.A. Keszei, Xiaoxiao Xu, Mahtab Heydari, Mary Elizabeth Hill, JoAnne McLaurin, Thomas Kislinger, Mohammad T. Mazhab-Jafari
{"title":"Unveiling the structural proteome of an Alzheimer’s disease rat brain model","authors":"Elnaz Khalili Samani, S.M. Naimul Hasan, Matthew Waas, Alexander F.A. Keszei, Xiaoxiao Xu, Mahtab Heydari, Mary Elizabeth Hill, JoAnne McLaurin, Thomas Kislinger, Mohammad T. Mazhab-Jafari","doi":"10.1016/j.str.2024.11.004","DOIUrl":"https://doi.org/10.1016/j.str.2024.11.004","url":null,"abstract":"Studying native protein structures at near-atomic resolution in a crowded environment presents challenges. Consequently, understanding the structural intricacies of proteins within pathologically affected tissues often relies on mass spectrometry and proteomic analysis. Here, we utilized cryoelectron microscopy (cryo-EM) and the Build and Retrieve (BaR) method to investigate protein complexes’ structural characteristics such as post-translational modification, active site occupancy, and arrested conformational state in Alzheimer’s disease (AD) using brain lysate from a rat model (TgF344-AD). Our findings reveal novel insights into the architecture of these complexes, corroborated through mass spectrometry analysis. Interestingly, it has been shown that the dysfunction of these protein complexes extends beyond AD, implicating them in cancer, as well as other neurodegenerative disorders such as Parkinson’s disease, Huntington’s disease, and schizophrenia. By elucidating these structural details, our work not only enhances our understanding of disease pathology but also suggests new avenues for future approaches in therapeutic intervention.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"9 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142742585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-25DOI: 10.1016/j.str.2024.10.032
Jingxia Chen, Xueyin Zhou, Yuqi Yang, Long Li
{"title":"Protein translocation through α-helical channels and insertases","authors":"Jingxia Chen, Xueyin Zhou, Yuqi Yang, Long Li","doi":"10.1016/j.str.2024.10.032","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.032","url":null,"abstract":"Protein translocation systems are essential for distributing proteins across various lipid membranes in cells. Cellular membranes, such as the endoplasmic reticulum (ER) membrane and mitochondrial inner membrane, require highly regulated protein translocation machineries that specifically allow the passage of protein polypeptides while blocking smaller molecules like ions and water. Key translocation systems include the Sec translocation channel, the protein insertases of the Oxa1 superfamily, and the translocases of the mitochondrial inner membrane (TIM). These machineries utilize different mechanisms to create pathways for proteins to move across membranes while preventing ion leakage during the dynamic translocation processes. In this review, we highlight recent advances in our understanding of these α-helical translocation machineries and examine their structures, mechanisms, and regulation. We also discuss the therapeutic potential of these translocation pathways and summarize the progress in drug development targeting these systems for treating diseases.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"80 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-22DOI: 10.1016/j.str.2024.10.031
Patryk Ludzia, Midori Ishii, Gauri Deák, Christos Spanos, Marcus D. Wilson, Christina Redfield, Bungo Akiyoshi
{"title":"The kinetoplastid kinetochore protein KKT23 acetyltransferase is a structural homolog of GCN5 that acetylates the histone H2A C-terminal tail","authors":"Patryk Ludzia, Midori Ishii, Gauri Deák, Christos Spanos, Marcus D. Wilson, Christina Redfield, Bungo Akiyoshi","doi":"10.1016/j.str.2024.10.031","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.031","url":null,"abstract":"The kinetochore is the macromolecular protein machine that drives chromosome segregation in eukaryotes. In an evolutionarily divergent group of organisms called kinetoplastids, kinetochores are built using a unique set of proteins (KKT1–25 and KKIP1–12). KKT23 is a constitutively localized kinetochore protein containing a C-terminal acetyltransferase domain of unknown function. Here, using X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy, we have determined the structure and dynamics of the KKT23 acetyltransferase domain from <em>Trypanosoma brucei</em> and found that it is structurally similar to the GCN5 histone acetyltransferase domain. We find that KKT23 can acetylate the C-terminal tail of histone H2A and that knockdown of KKT23 results in decreased H2A acetylation levels in <em>T. brucei</em>. Finally, we have determined the crystal structure of the N-terminal region of KKT23 and shown that it interacts with KKT22. Our study provides important insights into the structure and function of the unique kinetochore acetyltransferase in trypanosomes.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"11 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142690706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-21DOI: 10.1016/j.str.2024.10.030
Joao Ramos, Valerie Laux, Sax A. Mason, Marie-Hélène Lemée, Matthew W. Bowler, Kay Diederichs, Michael Haertlein, V. Trevor Forsyth, Estelle Mossou, Sine Larsen, Annette E. Langkilde
{"title":"Structure and dynamics of the active site of hen egg-white lysozyme from atomic resolution neutron crystallography","authors":"Joao Ramos, Valerie Laux, Sax A. Mason, Marie-Hélène Lemée, Matthew W. Bowler, Kay Diederichs, Michael Haertlein, V. Trevor Forsyth, Estelle Mossou, Sine Larsen, Annette E. Langkilde","doi":"10.1016/j.str.2024.10.030","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.030","url":null,"abstract":"Hen egg-white lysozyme (HEWL) is a widely used model protein in crystallographic studies and its enzymatic mechanism has been extensively investigated for decades. Despite this, the interaction between the reaction intermediate and the catalytic Asp52, as well as the orientation of Asn44 and Asn46 side chains, remain ambiguous. Here, we report the crystal structures of perdeuterated HEWL and D<sub>2</sub>O buffer-exchanged HEWL from 0.91 and 1.1 Å resolution neutron diffraction data, respectively. These structures were obtained at room temperature and acidic pH, representing the active state of the enzyme. The unambiguous assignment of hydrogen positions based on the neutron scattering length density maps elucidates the roles of Asn44, Asn46, Asn59, and nearby water molecules in the stabilization of Asp52. Additionally, the identification of hydrogen positions reveals unique details of lysozyme’s folding, hydrogen (H)/deuterium (D) exchange, and side chain disorder.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"99 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-19DOI: 10.1016/j.str.2024.10.028
Anna Yudenko, Sergey Bukhdruker, Pavel Shishkin, Sergey Rodin, Anastasia Burtseva, Aleksandr Petrov, Natalia Pigareva, Alexey Sokolov, Egor Zinovev, Igor Eliseev, Alina Remeeva, Egor Marin, Alexey Mishin, Valentin Gordeliy, Ivan Gushchin, Aleksandr Ischenko, Valentin Borshchevskiy
{"title":"Structural basis of signaling complex inhibition by IL-6 domain-swapped dimers","authors":"Anna Yudenko, Sergey Bukhdruker, Pavel Shishkin, Sergey Rodin, Anastasia Burtseva, Aleksandr Petrov, Natalia Pigareva, Alexey Sokolov, Egor Zinovev, Igor Eliseev, Alina Remeeva, Egor Marin, Alexey Mishin, Valentin Gordeliy, Ivan Gushchin, Aleksandr Ischenko, Valentin Borshchevskiy","doi":"10.1016/j.str.2024.10.028","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.028","url":null,"abstract":"Interleukin-6 (IL-6) is a multifaceted cytokine essential in many immune system processes and their regulation. It also plays a key role in hematopoiesis, and in triggering the acute phase reaction. IL-6 overproduction is critical in chronic inflammation associated with autoimmune diseases like rheumatoid arthritis and contributes to cytokine storms in COVID-19 patients. Over 20 years ago, researchers proposed that IL-6, which is typically monomeric, can also form dimers via a domain-swap mechanism, with indirect evidence supporting their existence. The physiological significance of IL-6 dimers was shown in B-cell chronic lymphocytic leukemia. However, no structures have been reported so far. Here, we present the crystal structure of an IL-6 domain-swapped dimer that computational approaches could not predict. The structure explains why the IL-6 dimer is antagonistic to the IL-6 monomer in signaling complex formation and provides insights for IL-6 targeted therapies.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"13 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-13DOI: 10.1016/j.str.2024.10.025
María Ángeles Márquez-Moñino, Clara M. Santiveri, Patricia de León, Sergio Camero, Ramón Campos-Olivas, M. Ángeles Jiménez, Margarita Sáiz, Beatriz González, José Manuel Pérez-Cañadillas
{"title":"The ALS drug riluzole binds to the C-terminal domain of SARS-CoV-2 nucleocapsid protein and has antiviral activity","authors":"María Ángeles Márquez-Moñino, Clara M. Santiveri, Patricia de León, Sergio Camero, Ramón Campos-Olivas, M. Ángeles Jiménez, Margarita Sáiz, Beatriz González, José Manuel Pérez-Cañadillas","doi":"10.1016/j.str.2024.10.025","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.025","url":null,"abstract":"Nucleoproteins (N) play an essential role in virus assembly and are less prone to mutation than other viral structural proteins, making them attractive targets for drug discovery. Using an NMR fragment-based drug discovery approach, we identified the 1,3-benzothiazol-2-amine (BZT) group as a scaffold to develop potential antivirals for SARS-CoV-2 nucleocapsid (N) protein. A thorough characterization of BZT derivatives using NMR, X-ray crystallography, antiviral activity assays, and intrinsic fluorescence measurements revealed their binding in the C-terminal domain (CTD) domain of the N protein, to residues Arg 259, Trp 330, and Lys 338, coinciding with the nucleotide binding site. Our most effective compound exhibits a slightly better affinity than GTP and the ALS drug riluzole, also identified during the screening, and displays notable viral inhibition activity. A virtual screening of 218 BZT-based compounds revealed a potential extended binding site that could be exploited for the future development of new SARS-CoV-2 antivirals.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"41 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structural and biochemical insights into the mechanism of the anti-CRISPR protein AcrIE3","authors":"Jasung Koo, Gyujin Lee, Changkon Park, Hyejin Oh, Sung-Hyun Hong, Jeong-Yong Suh, Euiyoung Bae","doi":"10.1016/j.str.2024.10.024","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.024","url":null,"abstract":"Anti-CRISPR (Acr) proteins are natural inhibitors of CRISPR-Cas systems, found in bacteriophages and other genetic elements. AcrIE3, identified in a <em>Pseudomonas</em> phage, inactivates the type I-E CRISPR-Cas system in <em>Pseudomonas aeruginosa</em> by engaging with the Cascade complex. However, its precise inhibition mechanism has remained elusive. In this study, we present a comprehensive structural and biochemical analysis of AcrIE3, providing mechanistic insight into its anti-CRISPR function. Our results reveal that AcrIE3 selectively binds to the Cas8e subunit of the Cascade complex. The crystal structure of AcrIE3 exhibits an all-helical fold with a negatively charged surface. Through extensive mutational analyses, we show that AcrIE3 interacts with the protospacer adjacent motif (PAM) recognition site in Cas8e through its negatively charged surface residues. These findings enhance our understanding of the structure and function of type I-E Acr proteins, suggesting PAM interaction sites as primary targets for divergent Acr inhibitors.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"95 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-13DOI: 10.1016/j.str.2024.10.026
Cheng Li, Yunqiang Bian, Yiting Tang, Lingyu Meng, Peipei Yin, Ye Hong, Jun Cheng, Yuchen Li, Jie Lin, Chao Tang, Chunlai Chen, Wenfei Li, Zhi Qi
{"title":"Deciphering the molecular mechanism underlying morphology transition in two-component DNA-protein cophase separation","authors":"Cheng Li, Yunqiang Bian, Yiting Tang, Lingyu Meng, Peipei Yin, Ye Hong, Jun Cheng, Yuchen Li, Jie Lin, Chao Tang, Chunlai Chen, Wenfei Li, Zhi Qi","doi":"10.1016/j.str.2024.10.026","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.026","url":null,"abstract":"Nucleic acid and protein co-condensates exhibit diverse morphologies crucial for fundamental cellular processes. Despite many previous studies that advanced our understanding of this topic, several interesting biophysical questions regarding the underlying molecular mechanisms remain. We investigated DNA and human transcription factor p53 co-condensates—a scenario where neither dsDNA nor the protein demonstrates phase-separation behavior individually. Through a combination of experimental assays and theoretical approaches, we elucidated: (1) the phase diagram of DNA-protein co-condensates at a certain observation time, identifying a phase transition between viscoelastic fluid and viscoelastic solid states, and a morphology transition from droplet-like to “pearl chain”-like co-condensates; (2) the growth dynamics of co-condensates. Droplet-like and “pearl chain”-like co-condensates share a common initial critical microscopic cluster size at the nanometer scale during the early stage of phase separation. These findings provide important insights into the biophysical mechanisms underlying multi-component phase separation within cellular environments.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"216 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-12DOI: 10.1016/j.str.2024.10.023
Neil J. Thomson, Ulrich Zachariae
{"title":"Mechanism of negative μ-opioid receptor modulation by sodium ions","authors":"Neil J. Thomson, Ulrich Zachariae","doi":"10.1016/j.str.2024.10.023","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.023","url":null,"abstract":"Negative allosteric modulation of G-protein coupled receptors (GPCRs) by Na<sup>+</sup> ions was first described in the 1970s for opioid receptors (ORs) and has subsequently been detected for most class A GPCRs. In high-resolution structures of inactive-state class A GPCRs, a Na<sup>+</sup> ion binds to a conserved pocket near residue D2.50, whereas active-state structures of GPCRs are incompatible with Na<sup>+</sup> binding. Correspondingly, Na<sup>+</sup> diminishes agonist affinity, stabilizes the receptors in the inactive state, and reduces basal signaling. We applied a mutual-information based analysis to <em>μ</em>s-timescale biomolecular simulations of the <em>μ</em>-opioid receptor (<em>μ</em>-OR). Our results reveal that Na<sup>+</sup> binding is coupled to a water wire linking the Na<sup>+</sup> binding site with the agonist binding pocket and to rearrangements in polar networks propagating conformational changes to the agonist and G-protein binding sites. These findings provide a new mechanistic link between the presence of the ion, altered agonist affinity, receptor deactivation, and lowered basal signaling levels.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"15 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
StructurePub Date : 2024-11-08DOI: 10.1016/j.str.2024.10.022
Fabian Liessmann, Lukas von Bredow, Jens Meiler, Ines Liebscher
{"title":"Targeting adhesion G protein-coupled receptors. Current status and future perspectives","authors":"Fabian Liessmann, Lukas von Bredow, Jens Meiler, Ines Liebscher","doi":"10.1016/j.str.2024.10.022","DOIUrl":"https://doi.org/10.1016/j.str.2024.10.022","url":null,"abstract":"G protein-coupled receptors (GPCRs) orchestrate many physiological functions and are a crucial target in drug discovery. Adhesion GPCRs (aGPCRs), the second largest family within this superfamily, are promising yet underexplored targets for treating various diseases, including obesity, psychiatric disorders, and cancer. However, the receptors’ unique and complex structure and miscellaneous interactions complicate comprehensive pharmacological studies. Despite recent progress in determining structures and elucidation of the activation mechanism, the function of many receptors remains to be determined.This review consolidates current knowledge on aGPCR ligands, focusing on small molecule orthosteric ligands and allosteric modulators identified for the ADGRGs subfamily (subfamily VIII), (GPR56/ADGRG1, GPR64/ADGRG2, GPR97/ADGRG3, GPR114/ADGRG5, GPR126/ADGRG6, and GPR128/ADGRG7). We discuss challenges in hit identification, target validation, and drug discovery, highlighting molecular compositions and recent structural breakthroughs. ADGRG ligands can offer new insights into aGPCR modulation and have significant potential for novel therapeutic interventions targeting various diseases.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"145 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}