I02-Macromolecular Crystallography
I03-Macromolecular Crystallography
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Sander
Herfst
,
Jie
Zhang
,
Mathilde
Richard
,
Ryan
Mcbride
,
Pascal
Lexmond
,
Theo M.
Bestebroer
,
Monique I. J.
Spronken
,
Dennis
De Meulder
,
Judith M.
Van Den Brand
,
Miruna E.
Rosu
,
Stephen R.
Martin
,
Steven J.
Gamblin
,
Xiaoli
Xiong
,
Wenjie
Peng
,
Rogier
Bodewes
,
Erhard
Van Der Vries
,
Albert D. M. E.
Osterhaus
,
James C.
Paulson
,
John J.
Skehel
,
Ron A. M.
Fouchier
Diamond Proposal Number(s):
[9826, 13775]
Abstract: In 2014, an outbreak of avian A/H10N7 influenza virus occurred among seals along North-European coastal waters, significantly impacting seal populations. Here, we examine the cross-species transmission and mammalian adaptation of this influenza A virus, revealing changes in the hemagglutinin surface protein that increase stability and receptor binding. The seal A/H10N7 virus was aerosol or respiratory droplet transmissible between ferrets. Compared with avian H10 hemagglutinin, seal H10 hemagglutinin showed stronger binding to the human-type sialic acid receptor, with preferential binding to α2,6-linked sialic acids on long extended branches. In X-ray structures, changes in the 220-loop of the receptor-binding pocket caused similar interactions with human receptor as seen for pandemic strains. Two substitutions made seal H10 hemagglutinin more stable than avian H10 hemagglutinin and similar to human hemagglutinin. Consequently, identification of avian-origin influenza viruses across mammals appears critical to detect influenza A viruses posing a major threat to humans and other mammals.
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Oct 2020
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I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[9826]
Abstract: Hemagglutinins (HAs) are the receptor-binding and membrane fusion glycoproteins of influenza viruses. They recognize sialic acid–containing, cell-surface glycoconjugates as receptors but have limited affinity for them, and, as a consequence, virus attachment to cells requires their interaction with several virus HAs. Receptor-bound virus is transferred into endosomes where membrane fusion by HAs is activated at pH between 5 and 6.5, depending on the strain of virus. Fusion activity requires extensive rearrangements in HA conformation that include extrusion of a buried “fusion peptide” to connect with the endosomal membrane, form a bridge to the virus membrane, and eventually bring both membranes close together. In this review, we give an overview of the structures of the 16 genetically and antigenically distinct subtypes of influenza A HA in relation to these two functions in virus replication and in relation to recognition of HA by antibodies that neutralize infection.
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Jun 2020
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I02-Macromolecular Crystallography
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Donald J.
Benton
,
Andrea
Nans
,
Lesley J.
Calder
,
Jack
Turner
,
Ursula
Neu
,
Yi Pu
Lin
,
Esther
Ketelaars
,
Nicole L.
Kallewaard
,
Davide
Corti
,
Antonio
Lanzavecchia
,
Steven
Gamblin
,
Peter B.
Rosenthal
,
John J.
Skehel
Diamond Proposal Number(s):
[9826]
Open Access
Abstract: Viruses with membranes fuse them with cellular membranes, to transfer their genomes into cells at the beginning of infection. For Influenza virus, the membrane glycoprotein involved in fusion is the hemagglutinin (HA), the 3D structure of which is known from X-ray crystallographic studies. The soluble ectodomain fragments used in these studies lacked the “membrane anchor” portion of the molecule. Since this region has a role in membrane fusion, we have determined its structure by analyzing the intact, full-length molecule in a detergent micelle, using cryo-EM. We have also compared the structures of full-length HA−detergent micelles with full-length HA−Fab complex detergent micelles, to describe an infectivity-neutralizing monoclonal Fab that binds near the ectodomain membrane anchor junction. We determine a high-resolution HA structure which compares favorably in detail with the structure of the ectodomain seen by X-ray crystallography; we detect, clearly, all five carbohydrate side chains of HA; and we find that the ectodomain is joined to the membrane anchor by flexible, eight-residue-long, linkers. The linkers extend into the detergent micelle to join a central triple-helical structure that is a major component of the membrane anchor.
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Oct 2018
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I02-Macromolecular Crystallography
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Diamond Proposal Number(s):
[9826]
Open Access
Abstract: The multi-protein complex WRAD, formed by WDR5, RbBP5, Ash2L and Dpy30, binds to the MLL SET domain to stabilize the catalytically active conformation required for histone H3K4 methylation. In addition, the WRAD complex contributes to the targeting of the activated complex to specific sites on chromatin. RbBP5 is central to MLL catalytic activation, by making critical contacts with the other members of the complex. Interestingly its only major structural domain, a canonical WD40 repeat β-propeller, is not implicated in this function. Here, we present the structure of the RbBP5 β-propeller domain revealing a distinct, feature rich surface, dominated by clusters of Arginine residues. Our nuclear magnetic resonance binding data supports the hypothesis that in addition to the role of RbBP5 in catalytic activation, its β-propeller domain is a platform for the recruitment of the MLL complexes to chromatin targets through its direct interaction with nucleic acids.
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Mar 2018
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I02-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Nicole l.
Kallewaard
,
Davide
Corti
,
Patrick J.
Collins
,
Ursula
Neu
,
Josephine M.
Mcauliffe
,
Ebony
Benjamin
,
Leslie
Wachter-Rosati
,
Frances J.
Palmer-Hill
,
Andy Q.
Yuan
,
Philip A.
Walker
,
Matthias
Vorleander
,
Siro
Bianchi
,
Barbara
Guarino
,
Anna
De marco
,
Fabrizia
Vanzetta
,
Gloria
Agatic
,
Mathilde
Foglierini
,
Debora
Pinna
,
Blanca
Fernandez-Rodriguez
,
Alexander
Fruehwirth
,
Chiara
Silacci
,
Roksana W.
Ogrodowicz
,
Stephen R.
Martin
,
Federica
Sallusto
,
Joann A.
Suzich
,
Antonio
Lanzavecchia
,
Qing
Zhu
,
Steven J.
Gamblin
,
John J.
Skehel
Diamond Proposal Number(s):
[9826]
Open Access
Abstract: Influenza virus remains a threat because of its ability to evade vaccine-induced immune responses due to antigenic drift. Here, we describe the isolation, evolution, and structure of a broad-spectrum human monoclonal antibody (mAb), MEDI8852, effectively reacting with all influenza A hemagglutinin (HA) subtypes. MEDI8852 uses the heavy-chain VH6-1 gene and has higher potency and breadth when compared to other anti-stem antibodies. MEDI8852 is effective in mice and ferrets with a therapeutic window superior to that of oseltamivir. Crystallographic analysis of Fab alone or in complex with H5 or H7 HA proteins reveals that MEDI8852 binds through a coordinated movement of CDRs to a highly conserved epitope encompassing a hydrophobic groove in the fusion domain and a large portion of the fusion peptide, distinguishing it from other structurally characterized cross-reactive antibodies. The unprecedented breadth and potency of neutralization by MEDI8852 support its development as immunotherapy for influenza virus-infected humans.
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Jul 2016
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I02-Macromolecular Crystallography
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Neil
Justin
,
Ying
Zhang
,
Cataldo
Tarricone
,
Stephen R.
Martin
,
Shuyang
Chen
,
Elizabeth
Underwood
,
Valeria
De Marco
,
Lesley F.
Haire
,
Philip A.
Walker
,
Danny
Reinberg
,
Jon R.
Wilson
,
Steven
Gamblin
Diamond Proposal Number(s):
[9826]
Open Access
Abstract: Polycomb repressive complex 2 (PRC2) silences gene expression through trimethylation of K27 of histone H3 (H3K27me3) via its catalytic SET domain. A missense mutation in the substrate of PRC2, histone H3K27M, is associated with certain pediatric brain cancers and is linked to a global decrease of H3K27me3 in the affected cells thought to be mediated by inhibition of PRC2 activity. We present here the crystal structure of human PRC2 in complex with the inhibitory H3K27M peptide bound to the active site of the SET domain, with the methionine residue located in the pocket that normally accommodates the target lysine residue. The structure and binding studies suggest a mechanism for the oncogenic inhibition of H3K27M. The structure also reveals how binding of repressive marks, like H3K27me3, to the EED subunit of the complex leads to enhancement of the catalytic efficiency of the SET domain and thus the propagation of this repressive histone modification.
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Apr 2016
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Xiaoli
Xiong
,
Davide
Corti
,
Junfeng
Liu
,
Debora
Pinna
,
Mathilde
Foglierini
,
Lesley J.
Calder
,
Stephen R.
Martin
,
Yi Pu
Lin
,
Phil
Walker
,
Patrick J.
Collins
,
Isabella
Monne
,
Amorsolo L.
Suguitan
,
Celia
Santos
,
Nigel J.
Temperton
,
Kanta
Subbarao
,
Antonio
Lanzavecchia
,
Steven
Gamblin
,
John J.
Skehel
Diamond Proposal Number(s):
[7707, 9826]
Open Access
Abstract: H5N1 avian influenza viruses remain a threat to public health mainly because they can cause severe infections in humans. These viruses are widespread in birds, and they vary in antigenicity forming three major clades and numerous antigenic variants. The most important features of the human monoclonal antibody FLD194 studied here are its broad specificity for all major clades of H5 influenza HAs, its high affinity, and its ability to block virus infection, in vitro and in vivo. As a consequence, this antibody may be suitable for anti-H5 therapy and as a component of stockpiles, together with other antiviral agents, for health authorities to use if an appropriate vaccine was not available. Our mutation and structural analyses indicate that the antibody recognizes a relatively conserved site near the membrane distal tip of HA, near to, but distinct from, the receptor-binding site. Our analyses also suggest that the mechanism of infectivity neutralization involves prevention of receptor recognition as a result of steric hindrance by the Fc part of the antibody. Structural analyses by EM indicate that three Fab fragments are bound to each HA trimer. The structure revealed by X-ray crystallography is of an HA monomer bound by one Fab. The monomer has some similarities to HA in the fusion pH conformation, and the monomer’s formation, which results from the presence of isopropanol in the crystallization solvent, contributes to considerations of the process of change in conformation required for membrane fusion.
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Jul 2015
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I02-Macromolecular Crystallography
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Serena
Sanulli
,
Neil
Justin
,
Aurélie
Teissandier
,
Katia
Ancelin
,
Manuela
Portoso
,
Matthieu
Caron
,
Audrey
Michaud
,
Berangère
Lombard
,
Simao t.
Da rocha
,
John
Offer
,
Damarys
Loew
,
Nicolas
Servant
,
Michel
Wassef
,
Fabienne
Burlina
,
Steven
Gamblin
,
Edith
Heard
,
Raphaël
Margueron
Diamond Proposal Number(s):
[9826]
Open Access
Abstract: Polycomb Group (PcG) proteins maintain transcriptional repression throughout development, mostly by regulating chromatin structure. Polycomb Repressive Complex 2 (PRC2), a component of the Polycomb machinery, is responsible for the methylation of histone H3 lysine 27 (H3K27me2/3). Jarid2 was previously identified as a cofactor of PRC2, regulating PRC2 targeting to chromatin and its enzymatic activity. Deletion of Jarid2 leads to impaired orchestration of gene expression during cell lineage commitment. Here, we reveal an unexpected crosstalk between Jarid2 and PRC2, with Jarid2 being methylated by PRC2. This modification is recognized by the Eed core component of PRC2 and triggers an allosteric activation of PRC2s enzymatic activity. We show that Jarid2 methylation is important to promote PRC2 activity at a locus devoid of H3K27me3 and for the correct deposition of this mark during cell differentiation. Our results uncover a regulation loop where Jarid2 methylation fine-tunes PRC2 activity depending on the chromatin context.
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Mar 2015
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I02-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[7707]
Open Access
Abstract: In 2004 an hemagglutinin 3 neuraminidase 8 (H3N8) equine influenza virus was transmitted from horses to dogs in Florida and subsequently spread throughout the United States and to Europe. To understand the molecular basis of changes in the antigenicity of H3 hemagglutinins (HAs) that have occurred during virus evolution in horses, and to investigate the role of HA in the equine to canine cross-species transfer, we used X-ray crystallography to determine the structures of the HAs from two antigenically distinct equine viruses and from a canine virus. Structurally all three are very similar with the majority of amino acid sequence differences between the two equine HAs located on the virus membrane-distal molecular surface. HAs of canine viruses are distinct in containing a Trp-222→Leu substitution in the receptor binding site that influences specificity for receptor analogs. In the fusion subdomain of canine and recent equine virus HAs a unique difference is observed by comparison with all other HAs examined to date. Analyses of site-specific mutant HAs indicate that a single amino acid substitution, Thr-30→Ser, influences interactions between N-terminal and C-terminal regions of the subdomain that are important in the structural changes required for membrane fusion activity. Both structural modifications may have facilitated the transmission of H3N8 influenza from horses to dogs.
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Jul 2014
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I02-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[7707]
Abstract: H10N8 follows H7N9 and H5N1 as the latest in a line of avian influenza viruses that cause serious disease in humans and have become a threat to public health1. Since December 2013, three human cases of H10N8 infection have been reported, two of whom are known to have died. To gather evidence relating to the epidemic potential of H10 we have determined the structure of the haemagglutinin of a previously isolated avian H10 virus and we present here results relating especially to its receptor-binding properties, as these are likely to be major determinants of virus transmissibility. Our results show, first, that the H10 virus possesses high avidity for human receptors and second, from the crystal structure of the complex formed by avian H10 haemagglutinin with human receptor, it is clear that the conformation of the bound receptor has characteristics of both the 1918 H1N1 pandemic virus2 and the human H7 viruses isolated from patients in 2013 (ref. 3). We conclude that avian H10N8 virus has sufficient avidity for human receptors to account for its infection of humans but that its preference for avian receptors should make avian-receptor-rich human airway mucins4 an effective block to widespread infection. In terms of surveillance, particular attention will be paid to the detection of mutations in the receptor-binding site of the H10 haemagglutinin that decrease its avidity for avian receptor, and could enable it to be more readily transmitted between humans.
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Jul 2014
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