|
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Justice O.
Amofa
,
Juergen
George
,
Noella A.
Okumu
,
Moses
Ohene
,
Ermias M.
Terefe
,
Stany L.
Tsomene
,
Oluwatodimu C.
Tougue
,
Ifeoluwa O.
Bejide
,
Kevin C.
Nabukeera
,
Anita Y.
Nelson
,
Carlos S. D.
Tagne
,
Patrick Y.
Osabutey
,
Aminata
Ndiaye
,
David O.
Nkwe
,
Emmanuel C.
Ohaekenyem
,
Tolulope F.
Jolaiya
,
Harrison
Banda
,
Omorede
Ikponmwosa-Eweka
,
Woutouoba
N. David
,
Blessing B.
Ekpenyong
,
Abdoulaye
Segda
,
Oudou
Diabate
,
Aliyi H.
Jarso
,
Kaddu
Arafat
,
Alyaa
Elrashedy
,
Mulatu M.
Yadeta
,
Zipporah B.
Richard
,
Isaac E.
Omara
,
Tshepang
Ndaba
,
Innocentmary I.
Ejiofor
,
Pierre F. R.
Magwell
,
Mohamed
Sedeek
,
Linda O.
Lazaro
,
Regan M.
Nyoni
,
Rossel A.
Oketch
,
Walter
Odur
,
Yaser M.
Hassan
,
Peris
Ambala
,
Courage
Chandipwisa
,
Osim P.
Bassey
,
Laurah N.
Ondari
,
Udokang G.
Jonah
,
Christelle A.
Amoussou
,
Racheal C.
Kyomukama
,
Cedric
Yamssi
,
Sunday C.
James
,
Abdoul K.
Kone
,
Oumar
Ndiaye
,
Henry
Ssenfuka
,
Agatha K.
Nyang’au
,
Yohana
Amos
,
Hakiimu
Kawalya
,
Bernard
Mware
,
Washingtone J.
Adundo
,
Vanessa B.
Ngannang-Fezeu
,
Alphonse G.
Tandja
,
Ahmed H.
Abdellatif
,
Oladokun F.
Omowumi
,
Nsubuga M.
Luutu
,
Angelo K. B.
Kouman
,
Doaa S.
Soliman
,
Nehemiah K.
Essilfie
,
James J.
Wabwile
,
Safiétou
Sankhe
,
Fatoumata G.
Fofana
,
Walid
Heiba
,
Yao
Nasser
,
Appolinaire
Djikeng
,
Eva
Akurut
,
Andrew
Walakira
,
Aurélien F. A.
Moumbock
,
Julia J.
Griese
,
Calvin
Tiengwe
,
Mama
Ndi
,
Itziar S.
Martin
,
Michel
Fodje
,
Nicolas V.
Rüffin
,
Katharina C.
Cramer
,
Jamaine
Davis
,
Emmanuel
Nji
Open Access
Abstract: Artificial intelligence is rapidly transforming structural biology and accelerating access to protein structures, yet many Africa-based scientists still lack infrastructure, training opportunities, and sustained mentorship to fully benefit. Here, we describe BioStruct-Africa’s community-driven framework integrating AlphaFold, experimental structural biology, and computational drug design to train 1000 scientists over the next decade.
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Feb 2026
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B21-High Throughput SAXS
|
María Florencia
Pignataro
,
Natalia Brenda
Fernández
,
Alba
Garay-Alvarez
,
María Florencia
Pavan
,
Rafael
Molina
,
Ines G.
Munoz
,
Julián
Grossi
,
Martín
Noguera
,
Antonella
Vila
,
Augusto E.
García
,
Hernán G.
Gentili
,
Naira Antonia
Rodríguez
,
Martín
Aran
,
Viviana
Parreño
,
Marina
Bok
,
Juan A.
Hermoso
,
Lorena Itatí
Ibañez
,
Javier
Santos
Diamond Proposal Number(s):
[35926]
Open Access
Abstract: Iron-sulfur clusters are essential cofactors for the accurate cellular function of many proteins. In eukaryotic cells, the biogenesis of most iron-sulfur clusters occurs in the mitochondria and involves the action of the Cys desulfurase supercomplex, which is activated by the protein frataxin (FXN). The decrease of FXN expression and/or function results in Friedreich’s ataxia (FRDA).
In this work, several nanobodies specific to human FXN were selected via phage display, demonstrating a wide range of effects on Cys desulfurase activity and a strong interaction with FXN. Nanobody interaction stabilized wild-type and FRDA-related FXN variants in vitro. FXN-nanobody complexes were characterized by NMR, SAXS, and X-ray crystallography. Additionally, Nanobody expression was studied in human cells. The subcellular localization, direct interaction with FXN by in situ proximity ligation assay, effect on cell viability, Fe-S-dependent enzymatic activities, and oxygen consumption rates were analyzed. Significantly, nanobody expression did not alter these key metabolic variables, suggesting that the interaction with FXN did not disrupt the pathway.
As a whole, our results suggest that nanobodies can serve as binding partners for mitochondrial FXN. However, the specific effect of the nanobodies on the conformational stability of FRDA-related FXN variants in cells should be investigated.
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Jan 2026
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I02-Macromolecular Crystallography
I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I23-Long wavelength MX
|
Jessica
Domenech
,
Nuttawan
Pramanpol
,
Claudine
Bisson
,
Sveta E.
Sedelnikova
,
Joshua R.
Barrett
,
Abdul A. A. B.
Dakhil
,
Vitaliy
Mykhaylyk
,
Ali S.
Abdelhameed
,
Stephen E.
Harding
,
David W.
Rice
,
Patrick J.
Baker
,
Juan
Ferrer
Diamond Proposal Number(s):
[300, 1218, 24447, 31850]
Open Access
Abstract: Enzymes from salt-in halophiles are stable in conditions of low water activity with applications in chiral synthesis requiring organic solvents, yet the origins of such stability remains poorly understood. Here we describe the molecular basis of the reaction mechanism and dual NADH/NADPH-specificity of D2HDH, a 2-hydroxyacid dehydrogenase from the extreme halophile Haloferax mediterranei, an organism whose proteins have to remain active in high intracellular concentrations of KCl. Halophilic adaptations of D2HDH include the expected acidic surface and a reduction in hydrophobic surface resulting from a lower lysine content. Structure determination of crystals of D2HDH grown with KCl showed that bound K+ ions were coordinated predominantly by clusters of main chain protein carbonyl ligands, with no involvement of the numerous exposed surface carboxyls. Structural comparisons identified similar sites in other halophilic proteins suggesting that the generic use of carbonyl clusters to coordinate K+ ions may also contribute in a carboxylate-independent way to the stabilisation of the folded state of the protein in its high salt environment.
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Aug 2025
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
|
Diamond Proposal Number(s):
[23269, 21265]
Open Access
Abstract: Mono-ADP-ribosyl transferase (mART) proteins are secreted virulence factors produced by several human pathogens, the founding member being diphtheria toxin (DT). Pseudomonas aeruginosa can also secrete a mART toxin, known as exotoxin A (PE), but with an organization of its three functional domains (receptor, translocation, and enzymatic elements) that is opposite to DT. Two additional PE-like toxins (PLTs) have been identified from Vibrio cholerae and Aeromonas hydrophila, suggesting more PLT family members may exist. Database mining discovered six additional putative homologues, considerably extending this group of PLTs across a wide range of bacterial species. Here, we examine sequence and structural information for these new family members with respect to previously identified PLTs. The X-ray crystal structures of four new homologues show the conservation of critical features responsible for structure and function. This study shows the potential of these newly described toxins for the development of novel drug delivery platforms. Additionally, genomic analysis suggests horizontal gene transfer to account for the wide distribution of PLTs across a range of eubacteria species, highlighting the need to monitor emerging pathogens and their virulence factors.
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Mar 2025
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Krios III-Titan Krios III at Diamond
|
Diamond Proposal Number(s):
[20287]
Open Access
Abstract: The Hsp70 chaperone system is capable of disassembling pathological aggregates such as amyloid fibres associated with serious degenerative diseases. Here we examine the role of the J-domain protein co-factor in amyloid disaggregation by the Hsc70 system. We used cryo-EM and tomography to compare the assemblies with wild-type DNAJB1 or inactive mutants. We show that DNAJB1 binds regularly along α-synuclein amyloid fibrils and acts in a 2-step recruitment of Hsc70, releasing DNAJB1 auto-inhibition before activating Hsc70 ATPase. The wild-type DNAJB1:Hsc70:Apg2 complex forms dense arrays of chaperones on the fibrils, with Hsc70 on the outer surface. When the auto-inhibition is removed by mutating DNAJB1 (ΔH5 DNAJB1), Hsc70 is recruited to the fibrils at a similar level, but the ΔH5 DNAJB1:Ηsc70:Apg2 complex is inactive, binds less regularly to the fibrils and lacks the ordered clusters. Therefore, we propose that 2-step activation of DNAJB1 regulates the ordered assembly of Hsc70 on the fibril. The localised, dense packing of chaperones could trigger a cascade of recruitment and activation to give coordinated, sequential binding and disaggregation from an exposed fibril end, as previously observed in AFM videos. This mechanism is likely to be important in maintaining a healthy cellular proteome into old age.
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Mar 2025
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I04-Macromolecular Crystallography
|
Diamond Proposal Number(s):
[29948]
Open Access
Abstract: Class I ribonucleotide reductases (RNRs) convert ribonucleotides into deoxyribonucleotides under oxic conditions. The R2 subunit provides a radical required for catalysis conducted by the R1 subunit. In most R2s the radical is generated on a tyrosine via oxidation by an adjacent metal site. The discovery of a metal-free R2 defined the new RNR subclass Ie. In R2e, three of the otherwise strictly conserved metal-binding glutamates in the active site are substituted. Two variants have been found, VPK and QSK. To date, the VPK version has been the focus of biochemical characterization. Here we characterize a QSK variant of R2e. We analyse the organismal distribution of the two R2e versions and find dozens of organisms relying solely on the QSK RNR for deoxyribonucleotide production. We demonstrate that the R2eQSK of the human pathogen Gardnerella vaginalis (Bifidobacterium vaginale) modifies the active site-adjacent tyrosine to DOPA. The amount of modified protein is shown to be dependent on coexpression with the other proteins encoded in the RNR operon. The DOPA containing R2eQSK can support ribonucleotide reduction in vitro while the unmodified protein cannot. Finally, we determined the first structures of R2eQSK in the unmodified and DOPA states.
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Feb 2025
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I03-Macromolecular Crystallography
|
Mara C.
Inniss
,
Sean G.
Smith
,
Dan Jun
Li
,
Benjamin
Primack
,
Dexue
Sun
,
Grace Y.
Olinger
,
Kerri-Lynn
Sheahan
,
Theresa
Ross
,
Meghan
Langley
,
Violet
Young
,
Andres
Alvarado
,
Shabnam
Davoodi
,
Jiefei
Geng
,
Michael
Schebesta
,
Michelle L.
Ols
,
Jeremy
Tchaicha
,
Jan
Ter Meulen
,
Dhruv K.
Sethi
Open Access
Abstract: Adoptive cell therapies (ACT) have shown reduced efficacy against solid tumor malignancies compared to hematologic malignancies, partly due to the immunosuppressive nature of the tumor microenvironment (TME). ACT efficacy may be enhanced with pleiotropic cytokines that remodel the TME; however, their expression needs to be tightly controlled to avoid systemic toxicities. Here we show T cells can be armored with membrane-bound cytokines with surface expression regulated using drug-responsive domains (DRDs) developed from the 260-amino acid protein human carbonic anhydrase 2 (CA2). The CA2-DRD can be stabilized in vitro and in vivo with the FDA-approved small-molecule CA2 inhibitor acetazolamide (ACZ). We develop conditional degrons using library-based screening of mutants and show characterization of one DRD using crystallography and molecular dynamics (MD) simulations. Using protein-engineering solutions to increase the valency of DRDs fused to the cargo we have developed “modulation hubs” and show tight regulation of membrane-bound cytokines IL2, IL12, IL15, IL21, IL23, and IFNα in genetically engineered T cells. Finally, CA2-DRD regulated IL12 mediates regulated efficacy in a solid tumor model. Regulation of pleotropic cytokines potentially paves the way to safely use these powerful cytokines in ACT for cancer treatment.
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Jan 2025
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B21-High Throughput SAXS
|
Sarah-Ana
Mitrovic
,
Chamalee
Demalgiriya-Gamage
,
Lisa-Maria
Winter
,
Tobias
Kiechle
,
Rebecca
Ebenhoch
,
Heike
Neubauer
,
Birgit
Stierstorfer
,
Lee
Frego
,
Christian
Wolfrum
,
Sophia
Reindl
,
Herbert
Nar
Diamond Proposal Number(s):
[26256]
Open Access
Abstract: GOLD domain seven-transmembrane helix (GOST) proteins form a new protein family involved in trafficking of membrane-associated cargo. They share a characteristic extracellular/luminal Golgi-dynamics (GOLD) domain, possibly responsible for ligand recognition. Based on structural homology, GPR180 is a new member of this protein family, but little is known about the cellular role of GPR180. Here we show the X-ray structure of the N-terminal domain of GPR180 (1.9 Å) and can confirm the homology to GOLD domains. Using cellular imaging we show the localization of GPR180 in intracellular vesicular structures implying its exposure to acidic pH environments. With Hydrogen/Deuterium Exchange-Mass Spectrometry (HDX-MS) we identify pH-dependent conformational changes, which can be mapped to a putative ligand binding site in the transmembrane region. The results reveal GPR180’s role in intracellular vesicles and offer insights into the pH-dependent function of this conserved GOST protein.
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Dec 2024
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B22-Multimode InfraRed imaging And Microspectroscopy
|
Diamond Proposal Number(s):
[27207]
Open Access
Abstract: There is cumulative evidence that lipid metabolism plays a key role in the pathogenesis of various neurodegenerative disorders including Alzheimer’s disease (AD). Visualising lipid content in a non-destructive label-free manner can aid in elucidating the AD phenotypes towards a better understanding of the disease. In this study, we combined multiple optical molecular-specific methods, Fourier transform infrared (FTIR) spectroscopic imaging, synchrotron radiation-infrared (SR-IR) microscopy, Raman and stimulated Raman scattering (SRS) microscopy, and optical-photothermal infrared (O-PTIR) microscopy with multivariate data analysis, to investigate the biochemistry of brain hippocampus in situ using a mouse model of tauopathy (rTg4510). We observed a significant difference in the morphology and lipid content between transgenic (TG) and wild type (WT) samples. Immunohistochemical staining revealed some degree of microglia co-localisation with elevated lipids in the brain. These results provide new evidence of tauopathy-related dysfunction in a preclinical study at a subcellular level.
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Oct 2024
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I03-Macromolecular Crystallography
|
Open Access
Abstract: The essential L,D-transpeptidase of Mycobacterium tuberculosis (LdtMt2) catalyses the formation of 33 cross-links in cell wall peptidoglycan and is a target for development of antituberculosis therapeutics. Efforts to inhibit LdtMt2 have been hampered by lack of knowledge of how it binds its substrate. To address this gap, we optimised the isolation of natural disaccharide tetrapeptide monomers from the Corynebacterium jeikeium bacterial cell wall through overproduction of the peptidoglycan sacculus. The tetrapeptides were used in binding / turnover assays and biophysical studies on LdtMt2. We determined a crystal structure of wild-type LdtMt2 reacted with its natural substrate, the tetrapeptide monomer of the peptidoglycan layer. This structure shows formation of a thioester linking the catalytic cysteine and the donor substrate, reflecting an intermediate in the transpeptidase reaction; it informs on the mode of entrance of the donor substrate into the LdtMt2 active site. The results will be useful in design of LdtMt2 inhibitors, including those based on substrate binding interactions, a strategy successfully employed for other nucleophilic cysteine enzymes.
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Sep 2024
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