I04-1-Macromolecular Crystallography (fixed wavelength)
I24-Microfocus Macromolecular Crystallography
|
Mingda
Ye
,
Mpho
Makola
,
Mark W.
Richards
,
Joseph A.
Newman
,
Michael
Fairhead
,
Selena G.
Burgess
,
Zhihuang
Wu
,
Elizabeth
Maclean
,
Nathan D.
Wright
,
Lizbe
Koekemoer
,
Andrew
Thompson
,
Gustavo
Arruda Bezerra
,
Gangshun
Yi
,
Huanyu
Li
,
Victor
Rangel
,
Dimitrios
Mamalis
,
Hazel
Aitkenhead
,
Benjamin G.
Davis
,
Robert J. C.
Gilbert
,
Katharina L.
Duerr
,
Richard
Bayliss
,
Opher
Gileadi
,
Frank
Von Delft
Diamond Proposal Number(s):
[26998]
Open Access
Abstract: Design of modular, transferable protein assemblies has broad applicability and in structural biology could help with the ever-troublesome crystallization bottleneck, including finding robustly behaved protein crystals for rapidly characterizing ligands or drug candidates or generating multiple polymorphs to illuminate diverse conformations. Nanobodies as crystallization chaperones are well-established but still unreliable, as we show here. Instead, we show an exemplar of how robust crystallization behavior can be engineered by exploring many combinations (>200) of nanobody surface mutations over several iterations. Critically, what needed testing was crystallization and diffraction quality, since target–nanobody binding affinity is decoupled from crystallizability enhancement. Our study yielded multiple polymorphs, all mediated by the same interface, with dramatically improved resolution and diffraction reliability for some mutants; we thus name them ‘Gluebodies’ (Gbs). We further demonstrate that these Gb mutations do transfer to some other targets, both for achieving robust crystallization in alternative packing forms and for establishing the ability to crystallize a key early stage readout. Since the Gb interface is evidently a favored interaction, it may be broadly applicable for modular assembly; more specifically, this work suggests that Gbs should be routinely attempted for crystallization whenever nanobodies are available.
|
Oct 2025
|
|
Krios I-Titan Krios I at Diamond
|
Gangshun
Yi
,
Dimitrios
Mamalis
,
Mingda
Ye
,
Loic
Carrique
,
Michael
Fairhead
,
Huanyu
Li
,
Katharina L.
Duerr
,
Peijun
Zhang
,
David B.
Sauer
,
Frank
Von Delft
,
Benjamin G.
Davis
,
Robert J. C.
Gilbert
Diamond Proposal Number(s):
[20223, 21004]
Open Access
Abstract: Whilst cryo-electron microscopy(cryo-EM) has become a routine methodology in structural biology, obtaining high-resolution cryo-EM structures of small proteins (<100 kDa) and increasing overall throughput remain challenging. One approach to augment protein size and improve particle alignment involves the use of binding proteins or protein-based scaffolds. However, a given imaging scaffold or linking module may prove inadequate for structure solution and availability of such scaffolds remains limited. Here, we describe a strategy that exploits covalent dimerization of nanobodies to trap an engineered, predisposed nanobody-to-nanobody interface, giving Di-Gembodies as modular constructs created in homomeric and heteromeric forms. By exploiting side-chain-to-side-chain assembly, they can simultaneously display two copies of the same or two distinct proteins through a subunit interface that provides sufficient constraint required for cryo-EM structure determination. We validate this method with multiple soluble and membrane structural targets, down to 14 kDa, demonstrating a flexible and scalable platform for expanded protein structure determination.
|
Aug 2025
|
|
I04-1-Macromolecular Crystallography (fixed wavelength)
I24-Microfocus Macromolecular Crystallography
|
Fouzia
Bano
,
Suneale
Banerji
,
Tao
Ni
,
Dixy E.
Green
,
Kalila R.
Cook
,
Iain W.
Manfield
,
Paul L.
Deangelis
,
Emanuele
Paci
,
Martin
Lepšík
,
Robert J. C.
Gilbert
,
Ralf P.
Richter
,
David G.
Jackson
Open Access
Abstract: Immune surveillance involves the continual migration of antigen-scavenging immune cells from the tissues to downstream lymph nodes via lymphatic vessels. To enable such passage, cells first dock with the lymphatic entry receptor LYVE-1 on the outer surface of endothelium, using their endogenous hyaluronan glycocalyx, anchored by a second hyaluronan receptor, CD44. Why the process should require two different hyaluronan receptors and by which specific mechanism the LYVE-1•hyaluronan interaction enables lymphatic entry is however unknown. Here we describe the crystal structures and binding mechanics of murine and human LYVE-1•hyaluronan complexes. These reveal a highly unusual, sliding mode of ligand interaction, quite unlike the conventional sticking mode of CD44, in which the receptor grabs free hyaluronan chain-ends and winds them in through conformational re-arrangements in a deep binding cleft, lubricated by a layer of structured waters. Our findings explain the mode of action of a dedicated lymphatic entry receptor and define a distinct, low tack adhesive interaction that enables migrating immune cells to slide through endothelial junctions with minimal resistance, while clinging onto their hyaluronan glycocalyx for essential downstream functions.
|
Mar 2025
|
|
Krios I-Titan Krios I at Diamond
Krios II-Titan Krios II at Diamond
Krios IV-Titan Krios IV at Diamond
|
Jianbing
Ma
,
Gangshun
Yi
,
Mingda
Ye
,
Craig
Macgregor-Chatwin
,
Yuewen
Sheng
,
Ying
Lu
,
Ming
Li
,
Qingrong
Li
,
Dong
Wang
,
Robert J. C.
Gilbert
,
Peijun
Zhang
Diamond Proposal Number(s):
[29812]
Open Access
Abstract: The cryo-electron microscopy (cryoEM) method has enabled high-resolution structure determination of numerous biomolecules and complexes. Nevertheless, cryoEM sample preparation of challenging proteins and complexes, especially those with low abundance or with preferential orientation, remains a major hurdle. We developed an affinity-grid method employing monodispersed single particle streptavidin on a lipid monolayer to enhance particle absorption on the grid surface and alleviate sample exposure to the air-water interface. Using this approach, we successfully enriched the Thermococcus kodakarensis mini-chromosome maintenance complex 3 (MCM3) on cryoEM grids through biotinylation and resolved its structure. We further utilized this affinity method to tether the biotin-tagged dsDNA to selectively enrich a stable MCM3-ATP-dsDNA complex for cryoEM structure determination. Intriguingly, both MCM3 apo and dsDNA bound structures exhibit left-handed open spiral conformations, distinct from other reported MCM structures. The large open gate is sufficient to accommodate a dsDNA which could potentially be melted. The value of mspSA affinity method was further demonstrated by mitigating the issue of preferential angular distribution of HIV-1 capsid protein hexamer and RNA polymerase II elongation complex from Saccharomyces cerevisiae.
|
Dec 2024
|
|
Krios I-Titan Krios I at Diamond
|
Diamond Proposal Number(s):
[20223, 21004]
Open Access
Abstract: Tumor-suppressor let-7 pre-microRNAs (miRNAs) are regulated by terminal uridylyltransferases TUT7 and TUT4 that either promote let-7 maturation by adding a single uridine nucleotide to the pre-miRNA 3′ end or mark them for degradation by the addition of multiple uridines. Oligo-uridylation is increased in cells by enhanced TUT7/4 expression and especially by the RNA-binding pluripotency factor LIN28A. Using cryogenic electron microscopy, we captured high-resolution structures of active forms of TUT7 alone, of TUT7 plus pre-miRNA and of both TUT7 and TUT4 bound with pre-miRNA and LIN28A. Our structures reveal that pre-miRNAs engage the enzymes in fundamentally different ways depending on the presence of LIN28A, which clamps them onto the TUTs to enable processive 3′ oligo-uridylation. This study reveals the molecular basis for mono- versus oligo-uridylation by TUT7/4, as determined by the presence of LIN28A, and thus their mechanism of action in the regulation of cell fate and in cancer.
|
Jul 2024
|
|
Krios I-Titan Krios I at Diamond
|
Diamond Proposal Number(s):
[20223, 21004]
Open Access
Abstract: Perforin-2 (PFN2, MPEG1) is a key pore-forming protein in mammalian innate immunity restricting intracellular bacteria proliferation. It forms a membrane-bound pre-pore complex that converts to a pore-forming structure upon acidification; but its mechanism of conformational transition has been debated. Here we used cryo-electron microscopy, tomography and subtomogram averaging to determine structures of PFN2 in pre-pore and pore conformations in isolation and bound to liposomes. In isolation and upon acidification, the pre-assembled complete pre-pore rings convert to pores in both flat ring and twisted conformations. On membranes, in situ assembled PFN2 pre-pores display various degrees of completeness; whereas PFN2 pores are mainly incomplete arc structures that follow the same subunit packing arrangements as found in isolation. Both assemblies on membranes use their P2 β-hairpin for binding to the lipid membrane surface. Overall, these structural snapshots suggest a molecular mechanism for PFN2 pre-pore to pore transition on a targeted membrane, potentially using the twisted pore as an intermediate or alternative state to the flat conformation, with the capacity to cause bilayer distortion during membrane insertion.
|
Oct 2022
|
|
I24-Microfocus Macromolecular Crystallography
|
Open Access
Abstract: Perforin-like proteins (PLPs) play key roles in mechanisms associated with parasitic disease caused by apicomplexans parasites Plasmodium and Toxoplasma. The T. gondii PLP1 (TgPLP1) mediates tachyzoite egress from cells, while the five Plasmodium PLPs carry out various roles in the life cycle of the parasite and with respect to the molecular basis of disease. Here we focus on Plasmodium vivax PLP1 and PLP2 (PvPLP1 and PvPLP2) compared to TgPLP1. Determination of the crystal structure of the membrane-binding APCβ domain of PvPLP1 reveals notable differences with TgPLP1, reflected in its inability to bind lipid bilayers as TgPLP1 and PvPLP2 do. Molecular dynamics simulations combined with site-directed mutagenesis and functional assays allow dissection of the binding interactions of TgPLP1 and PvPLP2 on lipid bilayers, and reveal similar tropisms for lipids enriched in the inner leaflet of the mammalian plasma membrane. In addition PvPLP2 displays a secondary synergistic interaction side-on from its principal bilayer interface. This study underlines the substantial differences between the biophysical properties of the APCβ domains of apicomplexan PLPs, which reflect their significant sequence diversity. Such differences will be important factors in determining the cell targeting and membrane-binding activity of the different proteins in parasitic life cycles and disease.
|
May 2022
|
|
I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
|
Samuel C.
Griffiths
,
Rebekka A.
Schwab
,
Kamel
El Omari
,
Benjamin
Bishop
,
Ellen J.
Iverson
,
Tomas
Malinauskas
,
Ramin
Dubey
,
Mingxing
Qian
,
Douglas F.
Covey
,
Robert J. C.
Gilbert
,
Rajat
Rohatgi
,
Christian
Siebold
Diamond Proposal Number(s):
[19946, 14744]
Open Access
Abstract: Hedgehog (HH) morphogen signalling, crucial for cell growth and tissue patterning in animals, is initiated by the binding of dually lipidated HH ligands to cell surface receptors. Hedgehog-Interacting Protein (HHIP), the only reported secreted inhibitor of Sonic Hedgehog (SHH) signalling, binds directly to SHH with high nanomolar affinity, sequestering SHH. Here, we report the structure of the HHIP N-terminal domain (HHIP-N) in complex with a glycosaminoglycan (GAG). HHIP-N displays a unique bipartite fold with a GAG-binding domain alongside a Cysteine Rich Domain (CRD). We show that HHIP-N is required to convey full HHIP inhibitory function, likely by interacting with the cholesterol moiety covalently linked to HH ligands, thereby preventing this SHH-attached cholesterol from binding to the HH receptor Patched (PTCH1). We also present the structure of the HHIP C-terminal domain in complex with the GAG heparin. Heparin can bind to both HHIP-N and HHIP-C, thereby inducing clustering at the cell surface and generating a high-avidity platform for SHH sequestration and inhibition. Our data suggest a multimodal mechanism, in which HHIP can bind two specific sites on the SHH morphogen, alongside multiple GAG interactions, to inhibit SHH signalling.
|
Dec 2021
|
|
I03-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
|
Tao
Ni
,
Fang
Jiao
,
Xiulian
Yu
,
Saša
Aden
,
Lucy
Ginger
,
Sophie I.
Williams
,
Fangfang
Bai
,
Vojtech
Prazak
,
Dimple
Karia
,
Phillip
Stansfeld
,
Peijun
Zhang
,
George
Munson
,
Gregor
Anderluh
,
Simon
Scheuring
,
Robert J. C.
Gilbert
Open Access
Abstract: Perforin-2 (MPEG1) is thought to enable the killing of invading microbes engulfed by macrophages and other phagocytes, forming pores in their membranes. Loss of perforin-2 renders individual phagocytes and whole organisms significantly more susceptible to bacterial pathogens. Here, we reveal the mechanism of perforin-2 activation and activity using atomic structures of pre-pore and pore assemblies, high-speed atomic force microscopy, and functional assays. Perforin-2 forms a pre-pore assembly in which its pore-forming domain points in the opposite direction to its membrane-targeting domain. Acidification then triggers pore formation, via a 180° conformational change. This novel and unexpected mechanism prevents premature bactericidal attack and may have played a key role in the evolution of all perforin family proteins.
|
Jan 2020
|
|
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
|
Diamond Proposal Number(s):
[10627]
Open Access
Abstract: Toxoplasma and Plasmodium are the parasitic agents of toxoplasmosis and malaria, respectively, and use perforin-like proteins (PLPs) to invade host organisms and complete their life cycles. The Toxoplasma gondii PLP1 (TgPLP1) is required for efficient exit from parasitophorous vacuoles in which proliferation occurs. We report structures of the membrane attack complex/perforin (MACPF) and Apicomplexan PLP C-terminal β-pleated sheet (APCβ) domains of TgPLP1. The MACPF domain forms hexameric assemblies, with ring and helix geometries, and the APCβ domain has a novel β-prism fold joined to the MACPF domain by a short linker. Molecular dynamics simulations suggest that the helical MACPF oligomer preserves a biologically important interface, whereas the APCβ domain binds preferentially through a hydrophobic loop to membrane phosphatidylethanolamine, enhanced by the additional presence of inositol phosphate lipids. This mode of membrane binding is supported by site-directed mutagenesis data from a liposome-based assay. Together, these structural and biophysical findings provide insights into the molecular mechanism of membrane targeting by TgPLP1.
|
Mar 2018
|
|
