Three-dimensional(3 D) reconstruction of icosahedral viruses has played a crucial role in the development of cryoelectron microscopy single-particle reconstruction, with many cryo-electron microscopy techniques firs...Three-dimensional(3 D) reconstruction of icosahedral viruses has played a crucial role in the development of cryoelectron microscopy single-particle reconstruction, with many cryo-electron microscopy techniques first established for structural studies of icosahedral viruses, owing to their high symmetry and large mass. This review summarizes the computational methods for icosahedral and symmetry-mismatch reconstruction of viruses, as well as the likely challenges and bottlenecks in virus reconstruction, such as symmetry mismatch reconstruction, contrast transformation function(CTF)correction, and particle distortion.展开更多
Recent technical breakthroughs in cryo-electron microscopy(cryo-EM) revolutionized structural biology, which led to the 2017 Nobel Prize in chemistry being awarded to three scientists, Jacques Dubochet, Joachim Fran...Recent technical breakthroughs in cryo-electron microscopy(cryo-EM) revolutionized structural biology, which led to the 2017 Nobel Prize in chemistry being awarded to three scientists, Jacques Dubochet, Joachim Frank, and Richard Henderson, who made groundbreaking contributions to the development of cryo-EM. In this review, I will give a comprehensive review of the developmental history of cryo-EM, the technical aspects of the breakthrough in cryo-EM leading to the structural biology revolution, including electron microscopy, image recording devices and image processing algorithms,and the major scientific achievements by Chinese researchers employing cryo-EM, covering protein complexes involved in or related to gene expression and regulation, protein synthesis and degradation, membrane proteins, immunity, and viruses.Finally, I will give a perspective outlook on the development of cryo-EM in the future.展开更多
The photosynthetic reaction center complex(RCC)of green sulfur bacteria(GSB)consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna–Matthews–Olson(FMO).Functionally,FMO...The photosynthetic reaction center complex(RCC)of green sulfur bacteria(GSB)consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna–Matthews–Olson(FMO).Functionally,FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs.In vivo,one RC was found to bind two FMOs,however,the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified.Here we report a structure of intact RCC which contains a RC core and two FMO trimers from a thermophilic green sulfur bacterium Chlorobaculum tepidum at 2.9A resolution by cryo-electron microscopy.The second FMO trimer is attached at the cytoplasmic side asymmetrically relative to the first FMO trimer reported previously.We also observed two new subunits(PscE and PscF)and the N-terminal transmembrane domain of a cytochrome-containing subunit(PscC)in the structure.These two novel subunits possibly function to facilitate the binding of FMOs to RC core and to stabilize the whole complex.A new bacteriochlorophyll(numbered as 816)was identified at the interspace between PscF and PscA-1,causing an asymmetrical energy transfer from the two FMO trimers to RC core.Based on the structure,we propose an energy transfer network within this photosynthetic apparatus.展开更多
Rabbit hemorrhagic disease was described in China in 1984 and can cause hemorrhagic necrosis of the liver within two or three days after infection.The etiological agent,rabbit hemorrhagic disease virus(RHDV),belongs t...Rabbit hemorrhagic disease was described in China in 1984 and can cause hemorrhagic necrosis of the liver within two or three days after infection.The etiological agent,rabbit hemorrhagic disease virus(RHDV),belongs to the Lagovirus genus in the Caliciviridae family.Compared to other calicivirus,such as rNV and SMSV,the structure of Lagovirus members is not well characterized.In this report,structures of two types of wild RHDV particles,the intact virion and the core-like particle(CLP),were reconstructed by cryo-electron microscopy at 11Åand 17Å,respectively.This is the first time the 3D structure of wild caliciviruses CLP has been provided,and the 3D structure of intact RHDV virion is the highest resolution structure in Lagovirus.Comparison of the intact virion and CLP structures clearly indicated that CLP was produced from the intact virion with the protrusion dissociated.In contrast with the crystal structures of recombinant Norovirus and San Miguel sea lion virus,the capsomers of RHDV virion exhibited unique structural features and assembly modes.Both P1 and P2 subdomains have interactions inside the AB capsomer,while only P2 subdomains have interaction inside CC capsomer.The pseudo atomic models of RHDV capsomers were constructed by homology modeling and density map fitting,and the rotation of RHDV VP60 P domain with respect to its S domain,compared with SMSV,was observed.Collectively,our cryo-electron microscopic studies of RHDV provide close insight into the structure of Lagovirus,which is important for functional analysis and better vaccine development in the future.展开更多
The fast development of electron microscopy has enabled unprecedented achievements in the field of life science and materials science[1–6].In particular,the 2017 Nobel Prize of chemistry was awarded to three scientis...The fast development of electron microscopy has enabled unprecedented achievements in the field of life science and materials science[1–6].In particular,the 2017 Nobel Prize of chemistry was awarded to three scientists who contributed significantly to developing cryo-electron microscopy(Cryo-EM)[7].This technique,involving fast freezing the biological samples using liquid nitrogen,was originally designed to keep"live cells"intact from water evaporation and crystallization and immune to展开更多
Chaperonins, a class of molecular chaperones, are oligomeric complexes acting as a protein-folding chamber in an ATP-dependent manner. Chaperonins have been classifed
Cryo-electron microscopy and image reconstruction were used to determine the three-dimensional structure of Infectious flacherie virus (IFV). 5047 particles were selected for the final reconstruction. The FSC curve sh...Cryo-electron microscopy and image reconstruction were used to determine the three-dimensional structure of Infectious flacherie virus (IFV). 5047 particles were selected for the final reconstruction. The FSC curve showed that the resolution of this capsid structure was 18 ·. The structure is a psuedo T=3 (P=3) icosahedral capsid with a diameter of 302.4 · and a single shell thickness of 15 ·. The density map showed that IFV has a smooth surface without any prominent protrude or depression. Comparison of the IFV structure with those of the insect picorna-like virus-Cricket paralysis virus (CrPV)and human picornavirus-Human rhinovirus 14 (HRV 14) revealed that the IFV structure resembles the CrPV structure. The "Rossmann canyon" is absent in both IFV and CrPV particles. The polypeptide topology of IFV VP2, IFV VP3 was predicted and the subunit location at the capsid surface was further analyzed.展开更多
Cryo-electron microscopic images of biological molecules usually have high noise and low contrast. It is essential to suppress noise and enhance contrast in order to recognize
Background:Cryo-electron microscopy(Cryo-EM)and tomography(Cryo-ET)have emerged as important imaging techniques for studying structures of macromolecular complexes.In 3D reconstruction of large macromolecular complexe...Background:Cryo-electron microscopy(Cryo-EM)and tomography(Cryo-ET)have emerged as important imaging techniques for studying structures of macromolecular complexes.In 3D reconstruction of large macromolecular complexes,many 2D projection images of macromolecular complex particles are usually acquired with low signal-tonoise ratio.Therefore,it is meaningful to select multiple images containing the same structure with identical orientation.The selected images are averaged to produce a higher-quality representation of the underlying structure with improved resolution.Existing approaches of selecting such images have limited accuracy and speed.Methods:We propose a simulated annealing-based algorithm(SA)to pick the homogeneous image set with best average.Its performance is compared with two baseline methods based on both 2D and 3D datasets.When tested on simulated and experimental 3D Cryo-ET images of Ribosome complex,SA sometimes stopped at a local optimal solution.Restarting is applied to settle this difficulty and significantly improved the performance of SA on 3D datasets.Results:Experimented on simulated and experimental 2D Cryo-EM images of Ribosome complex datasets respectively with SNR=10 and SNR=0.5,our method achieved better accuracy in terms of F-measure,resolution score,and time cost than two baseline methods.Additionally,SA shows its superiority when the proportion of homogeneous images decreases.Conclusions:SA is introduced for homogeneous image selection to realize higher accuracy with faster processing speed.Experiments on both simulated and real 2D Cryo-EM and 3D Cryo-ET images demonstrated that SA achieved expressively better performance.This approach serves as an important step for improving the resolution of structural recovery of macromolecular complexes captured by Cryo-EM and Cryo-ET.展开更多
Funded by the National Natural Science Foundation of China,Chinese Ministry of Science and Technology,and Chinese Academy of Sciences,ajoint team of three laboratories from the Institute of Biophysics of Chinese Acade...Funded by the National Natural Science Foundation of China,Chinese Ministry of Science and Technology,and Chinese Academy of Sciences,ajoint team of three laboratories from the Institute of Biophysics of Chinese Academy of Sciences,namely Liu Zhenfeng’s(柳振峰),Zhang展开更多
Recently, significant technical breakthroughs in both hardware equipment and software algorithms have enabled cryo-electron microscopy(cryo-EM) to become one of the most important techniques in biological structural a...Recently, significant technical breakthroughs in both hardware equipment and software algorithms have enabled cryo-electron microscopy(cryo-EM) to become one of the most important techniques in biological structural analysis. The technical aspects of cryo-EM define its unique advantages and the direction of development. As a rapidly emerging field, cryo-EM has benefitted from highly interdisciplinary research efforts. Here we review the current status of cryo-EM in the context of structural biology and discuss the technical challenges. It may eventually merge structural and cell biology at multiple scales.展开更多
Drug discovery is a crucial part of human healthcare and has dramatically benefited human lifespan and life quality in recent centuries, however, it is usually time-and effort-consuming. Structural biology has been de...Drug discovery is a crucial part of human healthcare and has dramatically benefited human lifespan and life quality in recent centuries, however, it is usually time-and effort-consuming. Structural biology has been demonstrated as a powerful tool to accelerate drug development. Among different techniques, cryo-electron microscopy(cryo-EM) is emerging as the mainstream of structure determination of biomacromolecules in the past decade and has received increasing attention from the pharmaceutical industry. Although cryo-EM still has limitations in resolution, speed and throughput, a growing number of innovative drugs are being developed with the help of cryo-EM. Here, we aim to provide an overview of how cryo-EM techniques are applied to facilitate drug discovery. The development and typical workflow of cryo-EM technique will be briefly introduced, followed by its specific applications in structure-based drug design, fragment-based drug discovery, proteolysis targeting chimeras, antibody drug development and drug repurposing. Besides cryo-EM, drug discovery innovation usually involves other state-of-the-art techniques such as artificial intelligence(AI), which is increasingly active in diverse areas. The combination of cryo-EM and AI provides an opportunity to minimize limitations of cryo-EM such as automation, throughput and interpretation of mediumresolution maps, and tends to be the new direction of future development of cryo-EM. The rapid development of cryo-EM will make it as an indispensable part of modern drug discovery.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0501100)the National Natural Science Foundation of China(Grant Nos.91530321,31570742,and 31570727)Science and Technology Planning Project of Hunan Province,China(Grant No.2017RS3033)
文摘Three-dimensional(3 D) reconstruction of icosahedral viruses has played a crucial role in the development of cryoelectron microscopy single-particle reconstruction, with many cryo-electron microscopy techniques first established for structural studies of icosahedral viruses, owing to their high symmetry and large mass. This review summarizes the computational methods for icosahedral and symmetry-mismatch reconstruction of viruses, as well as the likely challenges and bottlenecks in virus reconstruction, such as symmetry mismatch reconstruction, contrast transformation function(CTF)correction, and particle distortion.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0504700)the National Natural Science Foundation of China(Grant Nos.31570732 and 31770785)
文摘Recent technical breakthroughs in cryo-electron microscopy(cryo-EM) revolutionized structural biology, which led to the 2017 Nobel Prize in chemistry being awarded to three scientists, Jacques Dubochet, Joachim Frank, and Richard Henderson, who made groundbreaking contributions to the development of cryo-EM. In this review, I will give a comprehensive review of the developmental history of cryo-EM, the technical aspects of the breakthrough in cryo-EM leading to the structural biology revolution, including electron microscopy, image recording devices and image processing algorithms,and the major scientific achievements by Chinese researchers employing cryo-EM, covering protein complexes involved in or related to gene expression and regulation, protein synthesis and degradation, membrane proteins, immunity, and viruses.Finally, I will give a perspective outlook on the development of cryo-EM in the future.
基金supported by a National Natural Science Foundation of China (32100202 to J.H.C.)Natural Science Foundation of Zhejiang Province,China (LR22C010001 to J.H.C.)+1 种基金the National Key Research and Development Program of China (2018YFA0507700,2017YFA0504803 to X.Z.)the Fundamental Research Funds for the Central Universities (2018XZZX001-13 to X.Z.)。
文摘The photosynthetic reaction center complex(RCC)of green sulfur bacteria(GSB)consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna–Matthews–Olson(FMO).Functionally,FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs.In vivo,one RC was found to bind two FMOs,however,the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified.Here we report a structure of intact RCC which contains a RC core and two FMO trimers from a thermophilic green sulfur bacterium Chlorobaculum tepidum at 2.9A resolution by cryo-electron microscopy.The second FMO trimer is attached at the cytoplasmic side asymmetrically relative to the first FMO trimer reported previously.We also observed two new subunits(PscE and PscF)and the N-terminal transmembrane domain of a cytochrome-containing subunit(PscC)in the structure.These two novel subunits possibly function to facilitate the binding of FMOs to RC core and to stabilize the whole complex.A new bacteriochlorophyll(numbered as 816)was identified at the interspace between PscF and PscA-1,causing an asymmetrical energy transfer from the two FMO trimers to RC core.Based on the structure,we propose an energy transfer network within this photosynthetic apparatus.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.30700029,30721003)Chinese Academy of Sciences(KGCX1-YW-13)+1 种基金the National Basic Research Program(973 Program)(Nos.2006CB806506,2006CB911001)the National Programs for High Technology Research and Development Program(863 Program)(No.2006AA02Z173).
文摘Rabbit hemorrhagic disease was described in China in 1984 and can cause hemorrhagic necrosis of the liver within two or three days after infection.The etiological agent,rabbit hemorrhagic disease virus(RHDV),belongs to the Lagovirus genus in the Caliciviridae family.Compared to other calicivirus,such as rNV and SMSV,the structure of Lagovirus members is not well characterized.In this report,structures of two types of wild RHDV particles,the intact virion and the core-like particle(CLP),were reconstructed by cryo-electron microscopy at 11Åand 17Å,respectively.This is the first time the 3D structure of wild caliciviruses CLP has been provided,and the 3D structure of intact RHDV virion is the highest resolution structure in Lagovirus.Comparison of the intact virion and CLP structures clearly indicated that CLP was produced from the intact virion with the protrusion dissociated.In contrast with the crystal structures of recombinant Norovirus and San Miguel sea lion virus,the capsomers of RHDV virion exhibited unique structural features and assembly modes.Both P1 and P2 subdomains have interactions inside the AB capsomer,while only P2 subdomains have interaction inside CC capsomer.The pseudo atomic models of RHDV capsomers were constructed by homology modeling and density map fitting,and the rotation of RHDV VP60 P domain with respect to its S domain,compared with SMSV,was observed.Collectively,our cryo-electron microscopic studies of RHDV provide close insight into the structure of Lagovirus,which is important for functional analysis and better vaccine development in the future.
文摘The fast development of electron microscopy has enabled unprecedented achievements in the field of life science and materials science[1–6].In particular,the 2017 Nobel Prize of chemistry was awarded to three scientists who contributed significantly to developing cryo-electron microscopy(Cryo-EM)[7].This technique,involving fast freezing the biological samples using liquid nitrogen,was originally designed to keep"live cells"intact from water evaporation and crystallization and immune to
文摘Chaperonins, a class of molecular chaperones, are oligomeric complexes acting as a protein-folding chamber in an ATP-dependent manner. Chaperonins have been classifed
基金Supported by the National Natural Science Foundation of China (Grant No. 30370305)the National Basic Research and Development Program of China (Grant No. 2005CB121003)
文摘Cryo-electron microscopy and image reconstruction were used to determine the three-dimensional structure of Infectious flacherie virus (IFV). 5047 particles were selected for the final reconstruction. The FSC curve showed that the resolution of this capsid structure was 18 ·. The structure is a psuedo T=3 (P=3) icosahedral capsid with a diameter of 302.4 · and a single shell thickness of 15 ·. The density map showed that IFV has a smooth surface without any prominent protrude or depression. Comparison of the IFV structure with those of the insect picorna-like virus-Cricket paralysis virus (CrPV)and human picornavirus-Human rhinovirus 14 (HRV 14) revealed that the IFV structure resembles the CrPV structure. The "Rossmann canyon" is absent in both IFV and CrPV particles. The polypeptide topology of IFV VP2, IFV VP3 was predicted and the subunit location at the capsid surface was further analyzed.
文摘Cryo-electron microscopic images of biological molecules usually have high noise and low contrast. It is essential to suppress noise and enhance contrast in order to recognize
基金We thank Dr.Ming Sun for suggestions and Mr.Shan Zhou for initial exploratory studies.We thank Ms.Xindi Wu for helping with manuscript editingThis work was supported in part by U.S.National Institutes of Health(NIH)grant(P4l GM103712)+1 种基金MX acknowledges support from Samuel and Emma Winters FoundationXZ was supported by a fellowship from Carnegie Mellon University's Center for Machine Learning and Health.RJ is a RONG professor at the Institute for Data Science,Tsinghua University.
文摘Background:Cryo-electron microscopy(Cryo-EM)and tomography(Cryo-ET)have emerged as important imaging techniques for studying structures of macromolecular complexes.In 3D reconstruction of large macromolecular complexes,many 2D projection images of macromolecular complex particles are usually acquired with low signal-tonoise ratio.Therefore,it is meaningful to select multiple images containing the same structure with identical orientation.The selected images are averaged to produce a higher-quality representation of the underlying structure with improved resolution.Existing approaches of selecting such images have limited accuracy and speed.Methods:We propose a simulated annealing-based algorithm(SA)to pick the homogeneous image set with best average.Its performance is compared with two baseline methods based on both 2D and 3D datasets.When tested on simulated and experimental 3D Cryo-ET images of Ribosome complex,SA sometimes stopped at a local optimal solution.Restarting is applied to settle this difficulty and significantly improved the performance of SA on 3D datasets.Results:Experimented on simulated and experimental 2D Cryo-EM images of Ribosome complex datasets respectively with SNR=10 and SNR=0.5,our method achieved better accuracy in terms of F-measure,resolution score,and time cost than two baseline methods.Additionally,SA shows its superiority when the proportion of homogeneous images decreases.Conclusions:SA is introduced for homogeneous image selection to realize higher accuracy with faster processing speed.Experiments on both simulated and real 2D Cryo-EM and 3D Cryo-ET images demonstrated that SA achieved expressively better performance.This approach serves as an important step for improving the resolution of structural recovery of macromolecular complexes captured by Cryo-EM and Cryo-ET.
文摘Funded by the National Natural Science Foundation of China,Chinese Ministry of Science and Technology,and Chinese Academy of Sciences,ajoint team of three laboratories from the Institute of Biophysics of Chinese Academy of Sciences,namely Liu Zhenfeng’s(柳振峰),Zhang
文摘Recently, significant technical breakthroughs in both hardware equipment and software algorithms have enabled cryo-electron microscopy(cryo-EM) to become one of the most important techniques in biological structural analysis. The technical aspects of cryo-EM define its unique advantages and the direction of development. As a rapidly emerging field, cryo-EM has benefitted from highly interdisciplinary research efforts. Here we review the current status of cryo-EM in the context of structural biology and discuss the technical challenges. It may eventually merge structural and cell biology at multiple scales.
基金funded by the National Natural Science Foundation of China (NSFC, 31900046, 81972085, 82172465 and 32161133022)the Guangdong Provincial Key Laboratory of Advanced Biomaterials (2022B1212010003)+7 种基金the National Science and Technology Innovation 2030 Major Program (2022ZD0211900)the Shenzhen Key Laboratory of Computer Aided Drug Discovery (ZDSYS20201230165400001)the Chinese Academy of Science President’s International Fellowship Initiative (PIFI)(2020FSB0003)the Guangdong Retired Expert (granted by Guangdong Province)the Shenzhen Pengcheng ScientistNSFC-SNSF Funding (32161133022)Alpha Mol&SIAT Joint LaboratoryShenzhen Government Top-talent Working Funding and Guangdong Province Academician Work Funding。
文摘Drug discovery is a crucial part of human healthcare and has dramatically benefited human lifespan and life quality in recent centuries, however, it is usually time-and effort-consuming. Structural biology has been demonstrated as a powerful tool to accelerate drug development. Among different techniques, cryo-electron microscopy(cryo-EM) is emerging as the mainstream of structure determination of biomacromolecules in the past decade and has received increasing attention from the pharmaceutical industry. Although cryo-EM still has limitations in resolution, speed and throughput, a growing number of innovative drugs are being developed with the help of cryo-EM. Here, we aim to provide an overview of how cryo-EM techniques are applied to facilitate drug discovery. The development and typical workflow of cryo-EM technique will be briefly introduced, followed by its specific applications in structure-based drug design, fragment-based drug discovery, proteolysis targeting chimeras, antibody drug development and drug repurposing. Besides cryo-EM, drug discovery innovation usually involves other state-of-the-art techniques such as artificial intelligence(AI), which is increasingly active in diverse areas. The combination of cryo-EM and AI provides an opportunity to minimize limitations of cryo-EM such as automation, throughput and interpretation of mediumresolution maps, and tends to be the new direction of future development of cryo-EM. The rapid development of cryo-EM will make it as an indispensable part of modern drug discovery.