{"title":"Mechanism of phospho-Ubls’ specificity and conformational changes that regulate Parkin activity","authors":"Dipti Ranjan Lenka, Shradha Chaurasiya, Loknath Ratnakar, Atul Kumar","doi":"10.1016/j.str.2024.09.012","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.012","url":null,"abstract":"PINK1 and Parkin mutations lead to the early onset of Parkinson’s disease. PINK1-mediated phosphorylation of ubiquitin (Ub), ubiquitin-like protein (NEDD8), and ubiquitin-like (Ubl) domain of Parkin activate autoinhibited Parkin E3 ligase. The mechanism of various phospho-Ubls’ specificity and conformational changes leading to Parkin activation remain elusive. Herein, we show that compared to Ub, NEDD8 is a more robust binder and activator of Parkin. Structures and biophysical/biochemical data reveal specific recognition and underlying mechanisms of pUb/pNEDD8 and pUbl domain binding to the RING1 and RING0 domains, respectively. Also, pUb/pNEDD8 binding in the RING1 pocket promotes allosteric conformational changes in Parkin’s catalytic domain (RING2), leading to Parkin activation. Furthermore, Parkinson’s disease mutation K211N in the RING0 domain was believed to perturb Parkin activation due to loss of pUb binding. However, our data reveal allosteric conformational changes due to N211 that lock RING2 with RING0 to inhibit Parkin activity without disrupting pNEDD8/pUb binding.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"47 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374100","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 : 2024-10-03DOI: 10.1016/j.str.2024.09.008
Shuvankar Dey, Purba Pahari, Srija Mukherjee, James B. Munro, Dibyendu Kumar Das
{"title":"Conformational dynamics of SARS-CoV-2 Omicron spike trimers during fusion activation at single molecule resolution","authors":"Shuvankar Dey, Purba Pahari, Srija Mukherjee, James B. Munro, Dibyendu Kumar Das","doi":"10.1016/j.str.2024.09.008","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.008","url":null,"abstract":"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron entry involves spike (S) glycoprotein-mediated fusion of viral and late endosomal membranes. Here, using single-molecule Förster resonance energy transfer (sm-FRET) imaging and biochemical measurements, we directly visualized conformational changes of individual spike trimers on the surface of SARS-CoV-2 Omicron pseudovirions during fusion activation. We observed that the S2 domain of the Omicron spike is a dynamic fusion machine. S2 reversibly interchanges between the pre-fusion conformation and two previously undescribed intermediate conformations. Acidic pH shifts the conformational equilibrium of S2 toward an intermediate conformation and promotes the membrane hemi-fusion reaction. Moreover, we captured conformational reversibility in the S2 domain, which suggests that spike can protect itself from pre-triggering. Furthermore, we determined that Ca<sup>2+</sup> directly promotes the S2 conformational change from an intermediate conformation to post-fusion conformation. In the presence of a target membrane, low pH and Ca<sup>2+</sup> stimulate the irreversible transition to S2 post-fusion state and promote membrane fusion.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"222 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369154","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 : 2024-10-03Epub Date: 2024-08-15DOI: 10.1016/j.str.2024.07.015
Jana Škerlová, Jiří Brynda, Jan Šobotník, Marek Zákopčaník, Petr Novák, Thomas Bourguignon, David Sillam-Dussès, Pavlína Řezáčová
{"title":"Crystal structure of blue laccase BP76, a unique termite suicidal defense weapon.","authors":"Jana Škerlová, Jiří Brynda, Jan Šobotník, Marek Zákopčaník, Petr Novák, Thomas Bourguignon, David Sillam-Dussès, Pavlína Řezáčová","doi":"10.1016/j.str.2024.07.015","DOIUrl":"10.1016/j.str.2024.07.015","url":null,"abstract":"<p><p>Aging workers of the termite Neocapritermes taracua can defend their colony by sacrificing themselves by body rupture, mixing the externally stored blue laccase BP76 with hydroquinones to produce a sticky liquid rich in toxic benzoquinones. Here, we describe the crystal structure of BP76 isolated from N. taracua in its native form. The structure reveals several stabilization strategies, including compact folding, glycosylation, and flexible loops with disulfide bridges and tight dimer interface. The remarkable stability of BP76 maintains its catalytic activity in solid state during the lifespan of N. taracua workers, providing old workers with an efficient defensive weapon to protect their colony.</p>","PeriodicalId":22168,"journal":{"name":"Structure","volume":" ","pages":"1581-1585.e5"},"PeriodicalIF":4.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141996546","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 : 2024-10-03Epub Date: 2024-08-26DOI: 10.1016/j.str.2024.07.023
Daniel M Pinkas, Joshua C Bufton, Alice E Hunt, Charlotte E Manning, William Richardson, Alex N Bullock
{"title":"A BTB extension and ion-binding domain contribute to the pentameric structure and TFAP2A binding of KCTD1.","authors":"Daniel M Pinkas, Joshua C Bufton, Alice E Hunt, Charlotte E Manning, William Richardson, Alex N Bullock","doi":"10.1016/j.str.2024.07.023","DOIUrl":"10.1016/j.str.2024.07.023","url":null,"abstract":"<p><p>KCTD family proteins typically assemble into cullin-RING E3 ligases. KCTD1 is an atypical member that functions instead as a transcriptional repressor. Mutations in KCTD1 cause developmental abnormalities and kidney fibrosis in scalp-ear-nipple syndrome. Here, we present unexpected mechanistic insights from the structure of human KCTD1. Disease-causing mutation P20S maps to an unrecognized extension of the BTB domain that contributes to both its pentameric structure and TFAP2A binding. The C-terminal domain (CTD) shares its fold and pentameric assembly with the GTP cyclohydrolase I feedback regulatory protein (GFRP) despite lacking discernible sequence similarity. Most surprisingly, the KCTD1 CTD establishes a central channel occupied by alternating sodium and iodide ions that restrict TFAP2A dissociation. The elucidation of the structure redefines the KCTD1 BTB domain fold and identifies an unexpected ion-binding site for future study of KCTD1's function in the ectoderm, neural crest, and kidney.</p>","PeriodicalId":22168,"journal":{"name":"Structure","volume":" ","pages":"1586-1593.e4"},"PeriodicalIF":4.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142081553","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 : 2024-10-03DOI: 10.1016/j.str.2024.09.007
Radha Charan Dash, Gianluca A. Arianna, Seema M. Patel, Alessandro A. Rizzo, Noah J. Harrahill, Dmitry M. Korzhnev, M. Kyle Hadden
{"title":"Probing hot spots of protein-protein interactions mediated by the safety-belt region of REV7","authors":"Radha Charan Dash, Gianluca A. Arianna, Seema M. Patel, Alessandro A. Rizzo, Noah J. Harrahill, Dmitry M. Korzhnev, M. Kyle Hadden","doi":"10.1016/j.str.2024.09.007","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.007","url":null,"abstract":"REV7 is a HORMA (<u>H</u>op1, <u>R</u>ev7, <u>M</u>ad2) family adaptor protein best known as an accessory subunit of the translesion synthesis (TLS) DNA polymerase ζ (Polζ). In this role, REV7 binds REV3, the catalytic subunit of Polζ, by locking REV7-binding motifs (RBMs) in REV3 underneath the REV7 safety-belt loop. The same mechanism is used by REV7 to interact with RBMs from other proteins in DNA damage response (DDR) and mitosis. Because of the importance of REV7 for TLS and other DDR pathways, targeting REV7:RBM protein-protein interactions (PPIs) with small molecules has emerged as a strategy to enhance cancer response to genotoxic chemotherapy. To identify druggable pockets at the REV7:RBM interface, we performed computational analyses of REV7 complexed with several RBM partners. The contributions of different interface regions to REV7:RBM stabilization were corroborated experimentally. These studies provide insights into key intermolecular interactions and establish targetable regions of REV7 for the design of REV7:RBM PPI inhibitors.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"57 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369155","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 : 2024-10-03DOI: 10.1016/j.str.2024.09.009
Kristen M. Ramsey, Doug Barrick
{"title":"One RING to rule them all: Mind bomb-1 ccRING3 controls Notch signaling","authors":"Kristen M. Ramsey, Doug Barrick","doi":"10.1016/j.str.2024.09.009","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.009","url":null,"abstract":"In this issue of <em>Structure</em>, Cao et al.<span><span><sup>1</sup></span></span> use X-ray crystallography, biochemical, and genetic studies to define the key role of the Mind bomb-1 ccRING3 domain in triggering Notch signaling, and they demonstrate that ccRING3-mediated dimerization is a key step in ligand activation.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"202 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369157","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":"Aberrant tau condensates as catalytic microcompartments propel tau fibrillation","authors":"Agustín Mangiarotti, Asima Nayak, Dragomir Milovanovic","doi":"10.1016/j.str.2024.09.004","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.004","url":null,"abstract":"In this issue of <em>Structure,</em> Soeda et al.<span><span><sup>1</sup></span></span> employed optogenetic tools and demonstrate that an N-terminal truncation of tau and microtubule-binding deficiency lead to the formation of tau condensates, accelerating its fibrillation.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"63 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369675","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 : 2024-10-03DOI: 10.1016/j.str.2024.09.003
Lucas M.P. Chataigner, Bert J.C. Janssen
{"title":"First contact(in): The complete structure of contactin 2","authors":"Lucas M.P. Chataigner, Bert J.C. Janssen","doi":"10.1016/j.str.2024.09.003","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.003","url":null,"abstract":"In this issue of <em>Structure</em>, Fan et al.<span><span><sup>1</sup></span></span> report the structure of the full contactin 2 ectodomain, representing the first for the contactin family. The work reveals six immunoglobulin domains are essential for intercellular interactions, explores differences in proposed contactin 2 homodimerization mechanisms, and provides an updated model for contactin 2 organization on and between cells.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"16 11 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369156","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 : 2024-10-03DOI: 10.1016/j.str.2024.09.002
Mohit Misra, Ivan Ðikić
{"title":"Ubiquitous ubiquitin: From bacteria to eukaryotes","authors":"Mohit Misra, Ivan Ðikić","doi":"10.1016/j.str.2024.09.002","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.002","url":null,"abstract":"In a recent issue of <em>Nature</em>, Chambers et al.<span><span><sup>1</sup></span></span> combined bioinformatics, biochemistry, and X-ray crystallography to uncover the presence of a ubiquitin-like machinery in bacteria, which was believed to be unique to archaea and eukaryotes. This study highlights the prevalence of a ubiquitin-like system in bacteria that was later adopted by the eukaryotes for various purposes such as protein degradation.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"10 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369158","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 : 2024-09-30DOI: 10.1016/j.str.2024.09.005
Michaela Hovorková, Barbora Kaščáková, Lucie Petrásková, Petra Havlíčková, Jiří Nováček, Daniel Pinkas, Zdenko Gardian, Vladimír Křen, Pavla Bojarová, Ivana Kutá Smatanová
{"title":"The variable structural flexibility of the Bacillus circulans β-galactosidase isoforms determines their unique functionalities","authors":"Michaela Hovorková, Barbora Kaščáková, Lucie Petrásková, Petra Havlíčková, Jiří Nováček, Daniel Pinkas, Zdenko Gardian, Vladimír Křen, Pavla Bojarová, Ivana Kutá Smatanová","doi":"10.1016/j.str.2024.09.005","DOIUrl":"https://doi.org/10.1016/j.str.2024.09.005","url":null,"abstract":"β-Galactosidase from <em>Bacillus circulans</em> ATCC 31382 (BgaD) is a biotechnologically important enzyme for the synthesis of β-galactooligosaccharides (GOS). Among its four isoforms, isoform A (BgaD-A) has distinct synthetic properties. Here, we present cryoelectron microscopy (cryo-EM) structures of BgaD-A and compare them with the known X-ray crystal structure of isoform D (BgaD-D), revealing substantial structural divergences between the two isoforms. In contrast to BgaD-D, BgaD-A features a flexible Big-4 domain and another enigmatic domain. The newly identified flexible region in BgaD-A is termed as “barrier domain 8,” and serves as a barricade, obstructing the access of longer oligosaccharide substrates into the active site of BgaD-A. The transgalactosylation reactions catalyzed by both isoforms revealed that BgaD-A has a higher selectivity than BgaD-D in the earlier stages of the reaction and is prevailingly directed to shorter galactooligosaccharides. This study improves our understanding of the structural determinants governing β-galactosidase catalysis, with implications for tailored GOS production.","PeriodicalId":22168,"journal":{"name":"Structure","volume":"219 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330058","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}