To achieve de novo protein structure determination of challenging cases, multi-wavelength anomalous diffraction(MAD) and multiple isomorphous replacement(MIR) phasing can be powerful tools to obtain low-resolution ini...To achieve de novo protein structure determination of challenging cases, multi-wavelength anomalous diffraction(MAD) and multiple isomorphous replacement(MIR) phasing can be powerful tools to obtain low-resolution initial phases from heavy-atom derivative datasets, then phase extension is needed against high-resolution data to obtain accurate structures.In this context, we propose a direct-methods procedure here that could improve the initial low-resolution MAD/MIR phase quality.And accordingly, an automated process for extending initial phases to high resolution is also described.These two procedures are both implanted in the newly released IPCAS pipeline.Three cases are used to perform the test, including one set of 4.17 ? MAD data from a membrane protein and two sets of MAD/MIR data with derivatives truncated down to 6.80 ? and 6.90 ?, respectively.All the results have shown that the initial phases generated from the direct-methods procedure are better than that from the conventional MAD/MIR methods.The automated phase extensions for the latter two cases starting from 6.80 ? to 3.00 ? and 6.90 ? to 2.80 ? are proved to be successful, leading to complete models.This may provide convenient and reliable tools for phase improvement and phase extension in difficult low-resolution tasks.展开更多
Jingmenviruses are a group of flavi-like viruses with segmented genome and have been found in various types of hosts,including humans,cattle,monkeys,bats,rodents,sheep,ticks,mosquitoes and nematodes.Jingmenviruses,inc...Jingmenviruses are a group of flavi-like viruses with segmented genome and have been found in various types of hosts,including humans,cattle,monkeys,bats,rodents,sheep,ticks,mosquitoes and nematodes.Jingmenviruses,including the Jingmen tick virus(JMTV)and Alongshan virus(ALSV),have been associated with febrile illness and flu-like symptoms in humans.Viral polymerase plays critical roles in genome replication and transcription and is an ideal target for antiviral drugs.Here,we determined the crystal structures of RNA-dependent RNA polymerase(RdRp)domains of JMTV and ALSV at 2.6Åand 3.2Åresolutions,respectively.The overall structures of JMTV and ALSV RdRp domains are similar to those from the typical unsegmented viruses in Flaviviridae family,especially the Flavivirus genus.JMTV and ALSV RdRps can be divided into three subdomains and the catalytical Motif A-G are conserved like the typical flaviviruses,whereas the zinc-binding pockets are absent from the JMTV and ALSV RdRps.The 50-ends of jingmenvirus genomes are varied in length and sequence,and a highly conserved 8-nucleotide element located on the tip of stem loop A was identified and shown to be required for binding with RdRp and performing de novo replication activity.These findings provide important structural insights into RdRp of segmented flavivirus and reveal the key region of virus genome responsible for replication initiation,which would promote molecular understanding of segmented flavivirus replication and the structure-based design of antiviral drugs against flaviviruses.展开更多
Following the outbreak of coronavirus disease 2019(COVID-19),several severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)-related coronaviruses have been discovered.Previous research has identified a novel line...Following the outbreak of coronavirus disease 2019(COVID-19),several severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)-related coronaviruses have been discovered.Previous research has identified a novel lineage of SARS-CoV-2-related CoVs in bats,including RsYN04,which recognizes human angiotensin-converting enzyme 2(ACE2)and thus poses a potential threat to humans.Here,we screened the binding of the RsYN04receptor-binding domain(RBD)to ACE2 orthologs from 52animal species and found that the virus showed a narrower ACE2-binding spectrum than SARS-CoV-2.However,the presence of the T484W mutation in the RsYN04 RBD broadened its range.We also evaluated 44 SARS-CoV-2antibodies targeting seven epitope communities in the SARS-CoV-2 RBD,together with serum obtained from COVID-19 convalescents and vaccinees,to determine their cross-reaction against RsYN04.Results showed that no antibodies,except for the RBD-6 and RBD-7 classes,bound to the RsYN04 RBD,indicating substantial immune differences from SARS-CoV-2.Furthermore,the structure of the RsYN04 RBD in complex with cross-reactive antibody S43 in RBD-7 revealed a potently broad epitope for the development of therapeutics and vaccines.Our findings suggest RsYN04 and other viruses belonging to the same clade have the potential to infect several species,including humans,highlighting the necessity for viral surveillance and development of broad anticoronavirus countermeasures.展开更多
Almost all the neutralizing antibodies targeting the receptor-binding domain(RBD)of spike(S)protein show weakened or lost efficacy against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)emerged or emerging...Almost all the neutralizing antibodies targeting the receptor-binding domain(RBD)of spike(S)protein show weakened or lost efficacy against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)emerged or emerging variants,such as Omicron and its sub-variants.This suggests that highly conserved epitopes are crucial for the development of neutralizing antibodies.Here,we present one nanobody,N235,displaying broad neutralization against the SARS-CoV-2 prototype and multiple variants,including the newly emerged Omicron and its sub-variants.Cryo-electron microscopy demonstrates N235 binds a novel,conserved,cryptic epitope in the N-terminal domain(NTD)of the S protein,which interferes with the RBD in the neighboring S protein.The neutralization mechanism interpreted via flow cytometry and Western blot shows that N235 appears to induce the S1 subunit shedding from the trimeric S complex.Furthermore,a nano-IgM construct(MN235),engineered by fusing N235 with the human IgM Fc region,displays prevention via inducing S1 shedding and cross-linking virus particles.Compared to N235,MN235 exhibits varied enhancement in neutralization against pseudotyped and authentic viruses in vitro.The intranasal administration of MN235 in low doses can effectively prevent the infection of Omicron sub-variant BA.1 and XBB in vivo,suggesting that it can be developed as a promising prophylactic antibody to cope with the ongoing and future infection.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2011CB911100)of the Ministry of Science and Technology of China
文摘To achieve de novo protein structure determination of challenging cases, multi-wavelength anomalous diffraction(MAD) and multiple isomorphous replacement(MIR) phasing can be powerful tools to obtain low-resolution initial phases from heavy-atom derivative datasets, then phase extension is needed against high-resolution data to obtain accurate structures.In this context, we propose a direct-methods procedure here that could improve the initial low-resolution MAD/MIR phase quality.And accordingly, an automated process for extending initial phases to high resolution is also described.These two procedures are both implanted in the newly released IPCAS pipeline.Three cases are used to perform the test, including one set of 4.17 ? MAD data from a membrane protein and two sets of MAD/MIR data with derivatives truncated down to 6.80 ? and 6.90 ?, respectively.All the results have shown that the initial phases generated from the direct-methods procedure are better than that from the conventional MAD/MIR methods.The automated phase extensions for the latter two cases starting from 6.80 ? to 3.00 ? and 6.90 ? to 2.80 ? are proved to be successful, leading to complete models.This may provide convenient and reliable tools for phase improvement and phase extension in difficult low-resolution tasks.
基金funded by the grants from the National Key R&D Program of China(2021YFC2300200 to Q.P.and 2021YFC2300700 to Y.S.)Strategic Priority Research Program of CAS(XDB29010000 to Y.S.)+1 种基金National Natural Science Foundation of China(NSFC)(81871658 and 32192452 to Y.S.and 32100119 to Q.P.)Y.S.is also partially supported by the Youth Innovation Promotion Association of CAS(Y201921).
文摘Jingmenviruses are a group of flavi-like viruses with segmented genome and have been found in various types of hosts,including humans,cattle,monkeys,bats,rodents,sheep,ticks,mosquitoes and nematodes.Jingmenviruses,including the Jingmen tick virus(JMTV)and Alongshan virus(ALSV),have been associated with febrile illness and flu-like symptoms in humans.Viral polymerase plays critical roles in genome replication and transcription and is an ideal target for antiviral drugs.Here,we determined the crystal structures of RNA-dependent RNA polymerase(RdRp)domains of JMTV and ALSV at 2.6Åand 3.2Åresolutions,respectively.The overall structures of JMTV and ALSV RdRp domains are similar to those from the typical unsegmented viruses in Flaviviridae family,especially the Flavivirus genus.JMTV and ALSV RdRps can be divided into three subdomains and the catalytical Motif A-G are conserved like the typical flaviviruses,whereas the zinc-binding pockets are absent from the JMTV and ALSV RdRps.The 50-ends of jingmenvirus genomes are varied in length and sequence,and a highly conserved 8-nucleotide element located on the tip of stem loop A was identified and shown to be required for binding with RdRp and performing de novo replication activity.These findings provide important structural insights into RdRp of segmented flavivirus and reveal the key region of virus genome responsible for replication initiation,which would promote molecular understanding of segmented flavivirus replication and the structure-based design of antiviral drugs against flaviviruses.
基金supported by the National Key R&D Program of China (2022YFC2303403)National Natural Science Foundation of China (82225021)supported by the Chinese Academy of Sciences (YSBR-010 and Y2022037)。
文摘Following the outbreak of coronavirus disease 2019(COVID-19),several severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)-related coronaviruses have been discovered.Previous research has identified a novel lineage of SARS-CoV-2-related CoVs in bats,including RsYN04,which recognizes human angiotensin-converting enzyme 2(ACE2)and thus poses a potential threat to humans.Here,we screened the binding of the RsYN04receptor-binding domain(RBD)to ACE2 orthologs from 52animal species and found that the virus showed a narrower ACE2-binding spectrum than SARS-CoV-2.However,the presence of the T484W mutation in the RsYN04 RBD broadened its range.We also evaluated 44 SARS-CoV-2antibodies targeting seven epitope communities in the SARS-CoV-2 RBD,together with serum obtained from COVID-19 convalescents and vaccinees,to determine their cross-reaction against RsYN04.Results showed that no antibodies,except for the RBD-6 and RBD-7 classes,bound to the RsYN04 RBD,indicating substantial immune differences from SARS-CoV-2.Furthermore,the structure of the RsYN04 RBD in complex with cross-reactive antibody S43 in RBD-7 revealed a potently broad epitope for the development of therapeutics and vaccines.Our findings suggest RsYN04 and other viruses belonging to the same clade have the potential to infect several species,including humans,highlighting the necessity for viral surveillance and development of broad anticoronavirus countermeasures.
基金supported by the National Key R&D Program of China(2022YFC2303403)the National Science Fund for Distinguished Young Scholars(82225021)supported by the Young Scientists in Basic Research(YSBR-010).
文摘Almost all the neutralizing antibodies targeting the receptor-binding domain(RBD)of spike(S)protein show weakened or lost efficacy against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)emerged or emerging variants,such as Omicron and its sub-variants.This suggests that highly conserved epitopes are crucial for the development of neutralizing antibodies.Here,we present one nanobody,N235,displaying broad neutralization against the SARS-CoV-2 prototype and multiple variants,including the newly emerged Omicron and its sub-variants.Cryo-electron microscopy demonstrates N235 binds a novel,conserved,cryptic epitope in the N-terminal domain(NTD)of the S protein,which interferes with the RBD in the neighboring S protein.The neutralization mechanism interpreted via flow cytometry and Western blot shows that N235 appears to induce the S1 subunit shedding from the trimeric S complex.Furthermore,a nano-IgM construct(MN235),engineered by fusing N235 with the human IgM Fc region,displays prevention via inducing S1 shedding and cross-linking virus particles.Compared to N235,MN235 exhibits varied enhancement in neutralization against pseudotyped and authentic viruses in vitro.The intranasal administration of MN235 in low doses can effectively prevent the infection of Omicron sub-variant BA.1 and XBB in vivo,suggesting that it can be developed as a promising prophylactic antibody to cope with the ongoing and future infection.
