I24-Microfocus Macromolecular Crystallography
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Jos J. A. G.
Kamps
,
Philip
Hinchliffe
,
Johan
Glerup
,
Emily I.
Freeman
,
Pauline A.
Lang
,
Catherine
Tooke
,
Michael
Beer
,
Laura
Parkinson
,
Do-Heon
Gu
,
Sehan
Park
,
Nicholas
Devenish
,
Tiankun
Zhou
,
Anastasya
Shilova
,
Samanpreet
Kaur
,
Patrick
Rabe
,
Christopher J.
Schofield
,
James
Spencer
,
Jaehyun
Park
,
Robin L.
Owen
,
Allen M.
Orville
,
Pierre
Aller
Diamond Proposal Number(s):
[25260]
Open Access
Abstract: We describe the design and implementation of a drop-on-fixed-target method for time-resolved serial crystallography at both synchrotron and XFEL facilities. A piezoelectric droplet dispensing pipette is employed for addition of picolitre volume aqueous droplets (∼40–90 pl; ∼40–55 µm diameter sphere), containing (co-)substrate(s) or ligand(s), onto enzyme microcrystals previously loaded into the trapezoidal wells of an etched crystalline silicon fixed-target chip containing 25 600 wells in a high-density, square grid with 125 µm centre-to-centre well spacing. These features demand exquisite accuracy and thereby constrain motion controls to enable robust time-resolved crystallographic studies. The system was tested with three enzyme systems, comprising lysozyme and two β-lactamases, CTX-M-15 and AmpCEC. Mitigation strategies for cross-well contamination, including the implementation of interleaved controls, are described; the overall performance of the system at synchrotron and X-ray free-electron laser facilities was evaluated. This drop-on-fixed-target method is a reliable framework for time-resolved crystallography and will improve the consistency of measurements across facilities.
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Jul 2026
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Sakshi
Sharma
,
Peter A. C.
Wing
,
Wojtek
Trede
,
Shyam
Basak
,
Simeon D.
Draganov
,
Taylah
Andrews-Clark
,
Eidarus
Salah
,
Petra
Lukacik
,
Claire
Strain-Damerell
,
Adán
Pinto‐fernández
,
Martin A.
Walsh
,
Fernanda
Duarte
,
Christopher J.
Schofield
,
Lennart
Brewitz
Open Access
Abstract: The SARS-CoV-2 papain-like protease (PLpro) and the main protease (Mpro) catalyze hydrolysis of the viral polyproteins pp1a/1ab into functional nonstructural proteins. PLpro and Mpro are medicinal chemistry targets, with Mpro inhibitors being used for COVID-19 treatment. PLpro also catalyzes hydrolysis of ubiquitin and interferon-stimulated gene 15 (ISG15) from post-translationally modified human proteins. Here we report how screening of reported deubiquitinase inhibitors using solid-phase extraction coupled to mass spectrometry assays with oligopeptide substrates based on pp1a/1ab and on an ISG15-modified human protein enabled the identification of substrate-selective PLpro inhibitors. The results reveal that the deubiquitinase inhibitor ML364 selectively inhibits the deISGylase activity of isolated PLpro over its pp1a/1ab-processing activity. Structure-activity relationship and computational studies support the assignment of ML364 and derivatives as substrate-selective PLpro inhibitors. The combined results provide proof-of-concept for developing substrate-selective inhibitors of PLpro and, by implication, related proteolytic enzymes, including deubiquitinases.
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Jun 2026
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I03-Macromolecular Crystallography
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Monisha
Singha
,
Liam A.
Wilson
,
Elisabete C.
C. M. Moura
,
Maria M.
Trush
,
Karina
Calvopina
,
Gurleen
Kaur
,
Greta
Zaborskytė
,
Toms
Kalniņš
,
Tharindi
Panduwawala
,
Matthew J.
Bowen
,
Matthew J.
Beech
,
Jurgen
Brem
,
Peter J.
Mchugh
,
Edgars
Suna
,
Timothy R.
Walsh
,
Christopher J.
Schofield
,
Alistair J. M.
Farley
Diamond Proposal Number(s):
[31353]
Open Access
Abstract: Use of the clinically vital β-lactam antibiotics is increasingly compromised by resistance, commonly mediated by β-lactamases. While clinically used serine-β-lactamase (SBL) inhibitors have long been available, metallo-β-lactamase (MBL) inhibitors are not yet approved for clinical use. We report the structure-guided development of pyrrole-2-carboxylic acid derivatives as potent inhibitors of the clinically important di-Zn(II) ion containing B1 MBLs (NDM-1, VIM-1, VIM-2, IMP-1). Crystallographic studies reveal the pyrrole-2-carboxylic acids inhibit B1 MBLs via active site Zn(II)-coordination of the inhibitor carboxylate and trapping of the di-Zn(II) ion bridging hydroxide, the latter of which reacts with the substrate β-lactam ring during hydrolysis. Appropriately derivatized pyrrole-2-carboxylic acids enhance the activity of carbapenems against MBL producing Gram-negative clinical isolates. The results support further development of metalloenzyme inhibitors that exploit binding to structural or catalytically important water molecules, an approach which may help in achieving selectivity over other metalloenzymes compared to metal-chelation based approaches.
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May 2026
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Roman
Belle
,
John-Paul
Bukowski
,
Rachel
Schiller
,
Ronald
Cutler
,
Eidarus
Salah
,
Robert S.
Dawber
,
Anthony
Tumber
,
Joanna
Bonnici
,
Jessica D.
Kindrick
,
Loane
Serrano
,
Patrick
Rabe
,
Catrine
Johansson
,
Marie-Hélène
Ruchaud
,
Richard J.
Hopkinson
,
William D.
Figg
,
Paul E.
Brennan
,
David R.
Mole
,
Simone
Sidoli
,
Akane
Kawamura
,
Christopher J.
Schofield
Open Access
Abstract: Histone modifications, including Nε-lysine acetylation and methylation, play critical roles in the regulation of eukaryotic transcription. The addition of acetyl and methyl groups and removal of acetyl groups to histones involve redox-neutral reactions. Demethylation is O2-dependent, as reported for reactions catalysed by the 2-oxoglutarate-dependent hypoxia-inducible factor (HIF) hydroxylases, one of which is structurally related to the Jumonji-C (JmjC) histone demethylases. We screened for substrates of the HIF-regulated JmjC lysine demethylase KDM3A and unexpectedly observed that purified recombinant KDM3A catalyses oxidation of the Nε-acetyl group of the Lys-9 of histone H3 (H3K9ac) giving an Nε-hydroxyacetylated product (H3K9acOH). Here we show that Nε-hydroxyacetyl-lysine is recognized by proteins known to bind to H3K9ac, including histone deacetylases and the YEATS domain-containing AF9. Studies employing an Nε-hydroxyacetyl-lysine selective antibody and mass spectrometry support the cellular relevance of Nε-hydroxyacetyl-lysine. Our combined biochemical and cellular results provide evidence for an unanticipated O2-mediated link between histone lysine Nε-acetylation and JmjC catalysis.
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Apr 2026
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[23459]
Open Access
Abstract: Pseudomonas savastanoi pv. phaseolicola PK2 employs an Fe(II)-dependent ethylene/succinate-forming enzyme (PK2 PsEFE) to produce ethylene from 2-oxoglutarate (2OG). Here we report NMR-based assays showing that the putative P. savastanoi pv. glycinea PsEFE, which differs from PK2 PsEFE by a single residue, and the P. savastanoi pv.1449B PsEFE, which differs from PK2 PsEFE by 28 residues and a C-terminal 13-residue truncation, catalyze ethylene production from 2OG. Like the PK2 PsEFE, they catalyze oxidation of naturally occurring 2OG derivatives to give alcohol and diacid products. Crystallographic analysis demonstrates that the overall fold and active site of 1449B PsEFE is similar to that of PK2 PsEFE. Interestingly, 2OG was observed to adopt an atypical inverse metal ion binding mode in complex with 1449B PsEFE:Mn in which its 2-oxoacid group is positioned to interact with the guanidinium group of R277, but not the Mn ion, which substitutes for catalytically active Fe(II). Together with reported crystallographic results, this observation indicates that 2OG metal ion binding modes and conformations at the active sites of 2OG oxygenases can vary, possibly in a functionally or disease relevant manner.
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Mar 2026
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I03-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Mariska
De Munnik
,
Amelia
Brasnett
,
Tiankun
Zhou
,
William
Myers
,
Yicheng
Wang
,
Kuntal
Chatterjee
,
Anthony
Tumber
,
Stephen A.
Marshall
,
Philipp S.
Simon
,
Pierre
Aller
,
Anastasiia
Shilova
,
Danny
Axford
,
Hiroki
Makita
,
Daniel W.
Paley
,
Vandana
Tiwari
,
Alexander T.
Stead
,
Sebastian
Dehe
,
Humberto
Sanchez
,
Daniel J.
Rosenberg
,
Roberto
Alonso-Mori
,
Asmit
Bhowmick
,
Junko
Yano
,
Vittal K.
Yachandra
,
Jaehyun
Park
,
Sehan
Park
,
Allen M.
Orville
,
Lennart
Brewitz
,
Jan F.
Kern
,
Christopher J.
Schofield
,
Patrick
Rabe
Diamond Proposal Number(s):
[32727, 31353]
Open Access
Abstract: Protein-hydroxylation catalysed by Fe(II) and 2-oxoglutarate (2OG) dependent oxygenases is an important regulatory mechanism in human biology. Such oxygenases typically coordinate their Fe(II) cofactor via a conserved triad of an aspartate- or glutamate- and two histidine-residues. By contrast, aspartate/asparagine β-hydroxylase (AspH), which catalyses asparagine/aspartate-residue oxidation in epidermal growth factor-like domains (EGFDs), has only two histidine-residues (H679, H725), with a water occupying the site normally occupied by an aspartate- or glutamate-residue. We describe mechanistic studies with catalytically active AspH crystals. Turnover studies with single crystals under cryogenic conditions give (3 R)-hydroxylated EGFDs with the product alcohol coordinating Fe(II) trans to H725. Time-resolved serial crystallography of microcrystals using an acoustic droplet ejection system, coupled to X-ray emission analyses, demonstrate turnover within 1.5 s, giving a product complex in which Fe(II) is regenerated. Solution and crystallographic studies with the O2 surrogate nitric oxide imply O2 binds to Fe(II) trans to H725. The additional Fe-chelating water is maintained throughout AspH catalysis and is not directly involved in substrate hydroxylation, because O2 is the sole oxygen source in alcohol products, as shown by 18O labelling studies. The results reveal how AspH accommodates both aspartate- and asparagine-substrates and will assist in efforts targeting AspH for cancer treatment.
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Feb 2026
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[23459, 31353]
Open Access
Abstract: Traboulsi Syndrome is an autosomal recessive hereditary disease associated with developmental defects, in particular of the ocular system. Single nucleotide polymorphisms affecting the ASPH gene, which encodes for the 2-oxoglutarate (2OG)-dependent oxygenase aspartate/asparagine-β-hydroxylase (AspH), are associated with Traboulsi Syndrome. AspH catalyzes hydroxylations of conserved aspartate/asparagine residues in epidermal growth factor-like domain (EGFD) proteins. We report studies on the clinically-observed Traboulsi Syndrome-associated R688Q, R735Q, and R735W AspH variants. The results reveal that pathogenic active site substitutions substantially reduce, though do not ablate, EGFD hydroxylase activity compared to wildtype AspH. They imply that efficient AspH catalyzed EGFD hydroxylation is important during human development. Crystallographic studies reveal conservation of the overall AspH fold, but that the preferred conformations of 2OG in complex with the R735Q and R735W AspH variants differ from that with wildtype AspH. Screening of potential 2OG cosubstrate substitutes reveals certain 2-oxoacids, including naturally present metabolites, manifest enhanced catalytic efficiency of Traboulsi Syndrome-associated AspH variants compared to 2OG. The results thus provide proof-of-principle for a therapeutic strategy involving rescue of impaired activities of pathogenic active site AspH variants by use of 2-oxoacids, or 2-oxoacid precursors, other than 2OG.
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Dec 2025
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Open Access
Abstract: β-lactams demonstrate promising in vitro activity against Mycobacterium species and are being explored for tuberculosis treatment; however, evidence of their in vivo efficacy versus Mycobacterium tuberculosis remains limited. To achieve broad clinically relevant potency, optimization of the classical β-lactam scaffolds or development of new or non-β-lactam inhibitors for mycobacterial transpeptidases is likely required. In mycobacteria, potential targets of β-lactams include l,d-transpeptidases (Ldts) and penicillin-binding proteins (PBPs). Reports suggest that dual inhibition of Ldts and PBPs may be necessary to achieve effective anti-mycobacterial activity, yet the specific contributions of Ldt and PBP inhibition to the β-lactam antibacterial mechanisms are poorly understood. We used fluorogenic substrate mimics to investigate the effects of β-lactams and reported LdtMt2 inhibitors on Mycobacterium smegmatis (Msm), assessing their impacts on Ldt and PBP transpeptidase activities in living cells. The results reveal a statistically significant correlation between both Ldt and PBP inhibition and Msm growth suppression; under the tested conditions, a stronger correlation between Ldt inhibition and Msm growth suppression was observed. Notably, apparent inhibition of both PBPs and Ldts was observed with all active inhibitors, though β-lactams manifest increased potency of PBP inhibition. The combination of the β-lactams meropenem and faropenem with selected LdtMt2 inhibitors manifested an additive inhibitory effect against Msm. Our results highlight the importance of further optimizing β-lactam efficacy versus mycobacterial PBPs and Ldt transpeptidases.
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Sep 2025
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Joseph F.
Hoff
,
Kirsty E.
Goudar
,
Karina
Calvopina
,
Michael
Beer
,
Philip
Hinchliffe
,
John M.
Shaw
,
Catherine L.
Tooke
,
Yuiko
Takebayashi
,
Andrew F.
Cadzow
,
Nicholas
Harmer
,
Adrian J.
Mulholland
,
Christopher J.
Schofield
,
James
Spencer
Diamond Proposal Number(s):
[23269, 31440]
Open Access
Abstract: Carbapenemases, β-lactamases hydrolysing carbapenem antibiotics, challenge treatment of multi-drug resistant bacteria. The OXA-48 carbapenemase is widely disseminated in Enterobacterales, necessitating new treatments for producer strains. Diazabicyclooctane (DBO) inhibitors, including avibactam and nacubactam, act on a wide range of enzymes to overcome β-lactamase-mediated resistance. Here we investigate avibactam and nacubactam activities towards OXA-48 and two variants, OXA-163 and OXA-405, with deletions in the β5 – β6 loop neighbouring the active site that modify activity towards different β-lactam classes. Nacubactam is c. 80-fold less potent than avibactam towards OXA-48, but this difference reduces in OXA-163 and OXA-405. Crystal structures and molecular dynamics simulations reveal electrostatic repulsion between Arg214 on the OXA-48 β5 – β6 active-site loop and nacubactam, but not avibactam, effects absent from simulations of OXA-163 and OXA-405, which lack Arg214. Crystallographic and mass spectrometry data demonstrate that all three enzymes support desulfation of bound DBOs. These data indicate that interactions with Arg214 affect DBO potency, suggesting that sequence variation in OXA-48-like β-lactamases affects reactivity towards inhibitors as well as β-lactam substrates.
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Aug 2025
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Zihao
Wang
,
Guodong
Cao
,
Miranda P.
Collier
,
Xingyu
Qiu
,
Sophie
Broadway-Stringer
,
Dominik
Šaman
,
Jediael Z. Y.
Ng
,
Navoneel
Sen
,
Amar J.
Azad
,
Charlotte
Hooper
,
Johannes
Zimmermann
,
Michael A.
Mcdonough
,
Jurgen
Brem
,
Patrick
Rabe
,
Haigang
Song
,
T. Reid
Alderson
,
Christopher J.
Schofield
,
Jani R.
Bolla
,
Kristina
Djinovic-Carugo
,
Dieter O.
Fürst
,
Bettina
Warscheid
,
Matteo T.
Degiacomi
,
Timothy M.
Allison
,
Georg K. A.
Hochberg
,
Carol V.
Robinson
,
Katja
Gehmlich
,
Justin L. P.
Benesch
Diamond Proposal Number(s):
[19458]
Open Access
Abstract: The biomechanical properties and responses of tissues underpin a variety important of physiological functions and pathologies. In striated muscle, the actin-binding protein filamin C (FLNC) is a key protein whose variants causative for a wide range of cardiomyopathies and musculoskeletal pathologies. FLNC is a multi-functional protein that interacts with a variety of partners, however, how it is regulated at the molecular level is not well understood. Here we investigate its interaction with HSPB7, a cardiac-specific molecular chaperone whose absence is embryonically lethal. We find that FLNC and HSPB7 interact in cardiac tissue under biomechanical stress, forming a strong hetero-dimer whose structure we solve by X-ray crystallography. Our quantitative analyses show that the hetero-dimer out-competes the FLNC homo-dimer interface, potentially acting to abrogate the ability of the protein to cross-link the actin cytoskeleton, and to enhance its diffusive mobility. We show that phosphorylation of FLNC at threonine 2677, located at the dimer interface and associated with cardiac stress, acts to favour the homo-dimer. Conversely, phosphorylation at tyrosine 2683, also at the dimer interface, has the opposite effect and shifts the equilibrium towards the hetero-dimer. Evolutionary analysis and ancestral sequence reconstruction reveals this interaction and its mechanisms of regulation to date around the time primitive hearts evolved in chordates. Our work therefore shows, structurally, how HSPB7 acts as a specific molecular chaperone that regulates FLNC dimerisation.
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May 2025
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