{"title":"Cocrystal Structure of the Nocardia farcinica ileS T-box riboswitch in complex with its cognate tRNA","authors":"K. Suddala, J. Zhang","doi":"10.2210/pdb6ufm/pdb","DOIUrl":"https://doi.org/10.2210/pdb6ufm/pdb","url":null,"abstract":"","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":" ","pages":""},"PeriodicalIF":16.8,"publicationDate":"2019-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45348840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Protein cleavage inside the cell membrane triggers various pathophysiological signaling pathways, but the mechanism of catalysis is poorly understood. We solved ten structures of the Escherichia coli rhomboid protease in a bicelle membrane undergoing time-resolved steps that encompass the entire proteolytic reaction on a transmembrane substrate and an aldehyde inhibitor. Extensive gate opening accompanied substrate, but not inhibitor, binding, revealing that substrates and inhibitors take different paths to the active site. Catalysis unexpectedly commenced with, and was guided through subsequent catalytic steps by, motions of an extracellular loop, with local contributions from active site residues. We even captured the elusive tetrahedral intermediate that is uncleaved but covalently attached to the catalytic serine, about which the substrate was forced to bend dramatically. This unexpectedly stable intermediate indicates rhomboid catalysis uses an unprecedented reaction coordinate that may involve mechanically stressing the peptide bond, and could be selectively targeted by inhibitors. Time-resolved crystallography captures Escherichia coli rhomboid protease GlpG in different steps of catalysis, revealing how substrate reaches the active site and reaction intermediates.
{"title":"Time-resolved structural snapshot of proteolysis by GlpG inside the membrane","authors":"Sangwoo Cho, R. Baker, Ming Ji, S. Urban","doi":"10.2210/pdb6pj8/pdb","DOIUrl":"https://doi.org/10.2210/pdb6pj8/pdb","url":null,"abstract":"Protein cleavage inside the cell membrane triggers various pathophysiological signaling pathways, but the mechanism of catalysis is poorly understood. We solved ten structures of the Escherichia coli rhomboid protease in a bicelle membrane undergoing time-resolved steps that encompass the entire proteolytic reaction on a transmembrane substrate and an aldehyde inhibitor. Extensive gate opening accompanied substrate, but not inhibitor, binding, revealing that substrates and inhibitors take different paths to the active site. Catalysis unexpectedly commenced with, and was guided through subsequent catalytic steps by, motions of an extracellular loop, with local contributions from active site residues. We even captured the elusive tetrahedral intermediate that is uncleaved but covalently attached to the catalytic serine, about which the substrate was forced to bend dramatically. This unexpectedly stable intermediate indicates rhomboid catalysis uses an unprecedented reaction coordinate that may involve mechanically stressing the peptide bond, and could be selectively targeted by inhibitors. Time-resolved crystallography captures Escherichia coli rhomboid protease GlpG in different steps of catalysis, revealing how substrate reaches the active site and reaction intermediates.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"910-918"},"PeriodicalIF":16.8,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46100269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng Chen, K. Lam, Zheng Liu, Frank A. Mindlin, Baohua Chen, Craig B. Gutierrez, Lan Huang, Yongrong Zhang, Therwa Hamza, H. Feng, T. Matsui, M. Bowen, K. Perry, Rongsheng Jin
Clostridium difficile is an opportunistic pathogen that establishes in the colon when the gut microbiota are disrupted by antibiotics or disease. C. difficile infection (CDI) is largely caused by two virulence factors, TcdA and TcdB. Here, we report a 3.87-A-resolution crystal structure of TcdB holotoxin that captures a unique conformation of TcdB at endosomal pH. Complementary biophysical studies suggest that the C-terminal combined repetitive oligopeptides (CROPs) domain of TcdB is dynamic and can sample open and closed conformations that may facilitate modulation of TcdB activity in response to environmental and cellular cues during intoxication. Furthermore, we report three crystal structures of TcdB-antibody complexes that reveal how antibodies could specifically inhibit the activities of individual TcdB domains. Our studies provide novel insight into the structure and function of TcdB holotoxin and identify intrinsic vulnerabilities that could be exploited to develop new therapeutics and vaccines for the treatment of CDI.
{"title":"Structure of the pore forming fragment of Clostridium difficile toxin B in complex with VHH 5D","authors":"Peng Chen, K. Lam, Zheng Liu, Frank A. Mindlin, Baohua Chen, Craig B. Gutierrez, Lan Huang, Yongrong Zhang, Therwa Hamza, H. Feng, T. Matsui, M. Bowen, K. Perry, Rongsheng Jin","doi":"10.2210/PDB6OQ6/PDB","DOIUrl":"https://doi.org/10.2210/PDB6OQ6/PDB","url":null,"abstract":"Clostridium difficile is an opportunistic pathogen that establishes in the colon when the gut microbiota are disrupted by antibiotics or disease. C. difficile infection (CDI) is largely caused by two virulence factors, TcdA and TcdB. Here, we report a 3.87-A-resolution crystal structure of TcdB holotoxin that captures a unique conformation of TcdB at endosomal pH. Complementary biophysical studies suggest that the C-terminal combined repetitive oligopeptides (CROPs) domain of TcdB is dynamic and can sample open and closed conformations that may facilitate modulation of TcdB activity in response to environmental and cellular cues during intoxication. Furthermore, we report three crystal structures of TcdB-antibody complexes that reveal how antibodies could specifically inhibit the activities of individual TcdB domains. Our studies provide novel insight into the structure and function of TcdB holotoxin and identify intrinsic vulnerabilities that could be exploited to develop new therapeutics and vaccines for the treatment of CDI.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"712-719"},"PeriodicalIF":16.8,"publicationDate":"2019-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46209076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Júlia Batki, J. Schnabl, Juncheng Wang, Dominik Handler, Veselin I. Andreev, Christian E. Stieger, M. Novatchkova, Lisa Lampersberger, Kotryna Kauneckaitė, W. Xie, K. Mechtler, D. Patel, J. Brennecke
The PIWI-interacting RNA (piRNA) pathway protects genome integrity in part through establishing repressive heterochromatin at transposon loci. Silencing requires piRNA-guided targeting of nuclear PIWI proteins to nascent transposon transcripts, yet the subsequent molecular events are not understood. Here, we identify SFiNX (silencing factor interacting nuclear export variant), an interdependent protein complex required for Piwi-mediated cotranscriptional silencing in Drosophila. SFiNX consists of Nxf2–Nxt1, a gonad-specific variant of the heterodimeric messenger RNA export receptor Nxf1–Nxt1 and the Piwi-associated protein Panoramix. SFiNX mutant flies are sterile and exhibit transposon derepression because piRNA-loaded Piwi is unable to establish heterochromatin. Within SFiNX, Panoramix recruits heterochromatin effectors, while the RNA binding protein Nxf2 licenses cotranscriptional silencing. Our data reveal how Nxf2 might have evolved from an RNA transport receptor into a cotranscriptional silencing factor. Thus, NXF variants, which are abundant in metazoans, can have diverse molecular functions and might have been coopted for host genome defense more broadly. Identification of SFiNX, a complex of Nxf2–Nxt1, a variant of the mRNA export receptor Nxf1–Nxt1 and the Piwi-associated protein Panoramix, demonstrates an RNA export independent role for Nxf2 in piRNA-guided cotranscriptional transposon silencing.
{"title":"Crystal structure of dmNxf2 NTF2-like domain in complex with Nxt1/p15","authors":"Júlia Batki, J. Schnabl, Juncheng Wang, Dominik Handler, Veselin I. Andreev, Christian E. Stieger, M. Novatchkova, Lisa Lampersberger, Kotryna Kauneckaitė, W. Xie, K. Mechtler, D. Patel, J. Brennecke","doi":"10.2210/PDB6MRK/PDB","DOIUrl":"https://doi.org/10.2210/PDB6MRK/PDB","url":null,"abstract":"The PIWI-interacting RNA (piRNA) pathway protects genome integrity in part through establishing repressive heterochromatin at transposon loci. Silencing requires piRNA-guided targeting of nuclear PIWI proteins to nascent transposon transcripts, yet the subsequent molecular events are not understood. Here, we identify SFiNX (silencing factor interacting nuclear export variant), an interdependent protein complex required for Piwi-mediated cotranscriptional silencing in Drosophila. SFiNX consists of Nxf2–Nxt1, a gonad-specific variant of the heterodimeric messenger RNA export receptor Nxf1–Nxt1 and the Piwi-associated protein Panoramix. SFiNX mutant flies are sterile and exhibit transposon derepression because piRNA-loaded Piwi is unable to establish heterochromatin. Within SFiNX, Panoramix recruits heterochromatin effectors, while the RNA binding protein Nxf2 licenses cotranscriptional silencing. Our data reveal how Nxf2 might have evolved from an RNA transport receptor into a cotranscriptional silencing factor. Thus, NXF variants, which are abundant in metazoans, can have diverse molecular functions and might have been coopted for host genome defense more broadly. Identification of SFiNX, a complex of Nxf2–Nxt1, a variant of the mRNA export receptor Nxf1–Nxt1 and the Piwi-associated protein Panoramix, demonstrates an RNA export independent role for Nxf2 in piRNA-guided cotranscriptional transposon silencing.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"720-731"},"PeriodicalIF":16.8,"publicationDate":"2019-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47062235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The DNA and RNA processing protein TDP-43 undergoes both functional and pathogenic aggregation. Functional TDP-43 aggregates form reversible, transient species such as nuclear bodies, stress granules, and myo-granules. Pathogenic, irreversible TDP-43 aggregates form in amyotrophic lateral sclerosis and other neurodegenerative conditions. Here we find the features of TDP-43 fibrils that confer both reversibility and irreversibility by determining structures of two segments reported to be the pathogenic cores of human TDP-43 aggregation: SegA (residues 311-360), which forms three polymorphs, all with dagger-shaped folds; and SegB A315E (residues 286-331 containing the amyotrophic lateral sclerosis hereditary mutation A315E), which forms R-shaped folds. Energetic analysis suggests that the dagger-shaped polymorphs represent irreversible fibril structures, whereas the SegB polymorph may participate in both reversible and irreversible fibrils. Our structures reveal the polymorphic nature of TDP-43 and suggest how the A315E mutation converts the R-shaped polymorph to an irreversible form that enhances pathology.
{"title":"SegA-sym, conformation of TDP-43 low complexity domain segment A sym","authors":"Q. Cao, D. Boyer, M. Sawaya, P. Ge, D. Eisenberg","doi":"10.2210/PDB6N37/PDB","DOIUrl":"https://doi.org/10.2210/PDB6N37/PDB","url":null,"abstract":"The DNA and RNA processing protein TDP-43 undergoes both functional and pathogenic aggregation. Functional TDP-43 aggregates form reversible, transient species such as nuclear bodies, stress granules, and myo-granules. Pathogenic, irreversible TDP-43 aggregates form in amyotrophic lateral sclerosis and other neurodegenerative conditions. Here we find the features of TDP-43 fibrils that confer both reversibility and irreversibility by determining structures of two segments reported to be the pathogenic cores of human TDP-43 aggregation: SegA (residues 311-360), which forms three polymorphs, all with dagger-shaped folds; and SegB A315E (residues 286-331 containing the amyotrophic lateral sclerosis hereditary mutation A315E), which forms R-shaped folds. Energetic analysis suggests that the dagger-shaped polymorphs represent irreversible fibril structures, whereas the SegB polymorph may participate in both reversible and irreversible fibrils. Our structures reveal the polymorphic nature of TDP-43 and suggest how the A315E mutation converts the R-shaped polymorph to an irreversible form that enhances pathology.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"619-627"},"PeriodicalIF":16.8,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43627536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microtubules are regulated by post-translational modifications of tubulin. The ligation and cleavage of the carboxy-terminal tyrosine of α-tubulin impact microtubule functions during mitosis, cardiomyocyte contraction and neuronal processes. Tubulin tyrosination and detyrosination are mediated by tubulin tyrosine ligase and the recently discovered tubulin detyrosinases, vasohibin 1 and 2 (VASH1 and VASH2) bound to the small vasohibin-binding protein (SVBP). Here, we report the crystal structures of human VASH1-SVBP alone, in complex with a tyrosine-derived covalent inhibitor and bound to the natural product parthenolide. The structures and subsequent mutagenesis analyses explain the requirement for SVBP during tubulin detyrosination, and reveal the basis for the recognition of the C-terminal tyrosine and the acidic α-tubulin tail by VASH1. The VASH1-SVBP-parthenolide structure provides a framework for designing more effective chemical inhibitors of vasohibins, which can be valuable for dissecting their biological functions and may have therapeutic potential.
{"title":"Crystal structure of VASH1-SVBP complex bound with EpoY","authors":"Faxiang Li, Yingjie Hu, Shutao Qi, Xuelian Luo, Hongtao Yu","doi":"10.2210/PDB6OCG/PDB","DOIUrl":"https://doi.org/10.2210/PDB6OCG/PDB","url":null,"abstract":"Microtubules are regulated by post-translational modifications of tubulin. The ligation and cleavage of the carboxy-terminal tyrosine of α-tubulin impact microtubule functions during mitosis, cardiomyocyte contraction and neuronal processes. Tubulin tyrosination and detyrosination are mediated by tubulin tyrosine ligase and the recently discovered tubulin detyrosinases, vasohibin 1 and 2 (VASH1 and VASH2) bound to the small vasohibin-binding protein (SVBP). Here, we report the crystal structures of human VASH1-SVBP alone, in complex with a tyrosine-derived covalent inhibitor and bound to the natural product parthenolide. The structures and subsequent mutagenesis analyses explain the requirement for SVBP during tubulin detyrosination, and reveal the basis for the recognition of the C-terminal tyrosine and the acidic α-tubulin tail by VASH1. The VASH1-SVBP-parthenolide structure provides a framework for designing more effective chemical inhibitors of vasohibins, which can be valuable for dissecting their biological functions and may have therapeutic potential.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"583-591"},"PeriodicalIF":16.8,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46002638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Petria S. Thompson, K. M. Amidon, Kareem N. Mohni, D. Cortez, B. Eichman
Abasic (AP) sites are one of the most common DNA lesions that block replicative polymerases. 5-hydroxymethylcytosine binding, embryonic stem cell-specific protein (HMCES) recognizes and processes these lesions in the context of single-stranded DNA (ssDNA). A HMCES DNA-protein cross-link (DPC) intermediate is thought to shield the AP site from endonucleases and error-prone polymerases. The highly evolutionarily conserved SOS-response associated peptidase (SRAP) domain of HMCES and its Escherichia coli ortholog YedK mediate lesion recognition. Here we uncover the basis of AP site protection by SRAP domains from a crystal structure of the YedK DPC. YedK forms a stable thiazolidine linkage between a ring-opened AP site and the α-amino and sulfhydryl substituents of its amino-terminal cysteine residue. The thiazolidine linkage explains the remarkable stability of the HMCES DPC, its resistance to strand cleavage and the proteolysis requirement for resolution. Furthermore, its structure reveals that HMCES has specificity for AP sites in ssDNA at junctions found when replicative polymerases encounter the AP lesion.
碱基(AP)位点是阻断复制聚合酶的最常见的DNA损伤之一。5-羟甲基胞嘧啶结合，胚胎干细胞特异性蛋白(HMCES)在单链DNA (ssDNA)的背景下识别和处理这些病变。一种HMCES dna -蛋白交联(DPC)中间体被认为可以保护AP位点免受核酸内切酶和易出错聚合酶的攻击。HMCES的高度进化保守的sos反应相关肽酶(SRAP)结构域及其大肠杆菌同源YedK介导病变识别。本文从YedK DPC的晶体结构中揭示了SRAP结构域保护AP位点的基础。YedK在开环的AP位点与其氨基端半胱氨酸残基的α-氨基和巯基取代基之间形成稳定的噻唑烷键。噻唑烷键解释了HMCES DPC的显著稳定性，其抗链切割和蛋白水解要求的分辨率。此外，其结构表明，HMCES对复制聚合酶遇到AP病变时发现的ssDNA连接处的AP位点具有特异性。
{"title":"Non-covalent DNA-protein complex between E. coli YedK and ssDNA containing an abasic site analog","authors":"Petria S. Thompson, K. M. Amidon, Kareem N. Mohni, D. Cortez, B. Eichman","doi":"10.2210/PDB6NUH/PDB","DOIUrl":"https://doi.org/10.2210/PDB6NUH/PDB","url":null,"abstract":"Abasic (AP) sites are one of the most common DNA lesions that block replicative polymerases. 5-hydroxymethylcytosine binding, embryonic stem cell-specific protein (HMCES) recognizes and processes these lesions in the context of single-stranded DNA (ssDNA). A HMCES DNA-protein cross-link (DPC) intermediate is thought to shield the AP site from endonucleases and error-prone polymerases. The highly evolutionarily conserved SOS-response associated peptidase (SRAP) domain of HMCES and its Escherichia coli ortholog YedK mediate lesion recognition. Here we uncover the basis of AP site protection by SRAP domains from a crystal structure of the YedK DPC. YedK forms a stable thiazolidine linkage between a ring-opened AP site and the α-amino and sulfhydryl substituents of its amino-terminal cysteine residue. The thiazolidine linkage explains the remarkable stability of the HMCES DPC, its resistance to strand cleavage and the proteolysis requirement for resolution. Furthermore, its structure reveals that HMCES has specificity for AP sites in ssDNA at junctions found when replicative polymerases encounter the AP lesion.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"613-618"},"PeriodicalIF":16.8,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42837871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The human equilibrative nucleoside transporter 1 (hENT1), a member of the SLC29 family, plays crucial roles in adenosine signaling, cellular uptake of nucleoside for DNA and RNA synthesis, and nucleoside-derived anticancer and antiviral drug transport in humans. Because of its central role in adenosine signaling, it is the target of adenosine reuptake inhibitors (AdoRI), several of which are used clinically. Despite its importance in human physiology and pharmacology, the molecular basis of hENT1-mediated adenosine transport and its inhibition by AdoRIs are limited, owing to the absence of structural information on hENT1. Here, we present crystal structures of hENT1 in complex with two chemically distinct AdoRIs: dilazep and S-(4-nitrobenzyl)-6-thioinosine (NBMPR). Combined with mutagenesis study, our structural analyses elucidate two distinct inhibitory mechanisms exhibited on hENT1 and provide insight into adenosine recognition and transport. Our studies provide a platform for improved pharmacological intervention of adenosine and nucleoside analog drug transport by hENT1.
{"title":"Human equilibrative nucleoside transporter-1, S-(4-nitrobenzyl)-6-thioinosine bound, merohedrally twinned","authors":"Nicholas Wright, Seok-Yong Lee","doi":"10.2210/PDB6OB6/PDB","DOIUrl":"https://doi.org/10.2210/PDB6OB6/PDB","url":null,"abstract":"The human equilibrative nucleoside transporter 1 (hENT1), a member of the SLC29 family, plays crucial roles in adenosine signaling, cellular uptake of nucleoside for DNA and RNA synthesis, and nucleoside-derived anticancer and antiviral drug transport in humans. Because of its central role in adenosine signaling, it is the target of adenosine reuptake inhibitors (AdoRI), several of which are used clinically. Despite its importance in human physiology and pharmacology, the molecular basis of hENT1-mediated adenosine transport and its inhibition by AdoRIs are limited, owing to the absence of structural information on hENT1. Here, we present crystal structures of hENT1 in complex with two chemically distinct AdoRIs: dilazep and S-(4-nitrobenzyl)-6-thioinosine (NBMPR). Combined with mutagenesis study, our structural analyses elucidate two distinct inhibitory mechanisms exhibited on hENT1 and provide insight into adenosine recognition and transport. Our studies provide a platform for improved pharmacological intervention of adenosine and nucleoside analog drug transport by hENT1.","PeriodicalId":18836,"journal":{"name":"Nature Structural &Molecular Biology","volume":"26 1","pages":"599-606"},"PeriodicalIF":16.8,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44664546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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