E01-JEM ARM 200CF
E02-JEM ARM 300CF
I18-Microfocus Spectroscopy
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N.
Topping
,
J. C.
Bridges
,
L. J.
Hicks
,
L.
Petera
,
C. S.
Allen
,
J.
Ryu
,
D. G.
Hopkinson
,
M.
Danaie
,
L.
Blase
,
F. M.
Willcocks
,
G.
Douglas
,
H. G.
Changela
,
T.
Noguchi
,
T.
Matsumoto
,
A.
Miyake
Diamond Proposal Number(s):
[30752, 31953, 32874, 35976, 29615, 31641, 35046]
Open Access
Abstract: A correlative multi-technique approach, including electron microscopy and X-ray synchrotron work, has been used to obtain both structural and compositional information of a sulfur-bearing serpentine identified in several carbonaceous chondrites (Winchcombe CM2, Aguas Zarcas CM2, Ivuna CI, and Orgueil CI), and in Ryugu samples returned by the Hayabusa2 mission. S-K edge X-ray absorption spectroscopy was used to determine the oxidation state of sulfur in the serpentine in all samples except Ryugu. The abundance of this phase varies across these samples, with the largest amount in Winchcombe; ~12 vol% of phyllosilicates are identified as sulfur-bearing serpentine characterized by ~10 wt% SO3 equivalent. HRTEM studies reveal a d001-spacing range of 0.64–0.70 nm across all sulfur-bearing serpentine sites, averaging 0.68 nm, characteristic of serpentine. Sulfur-serpentine has variable S6+/ΣStotal values and different sulfur species dependent on specimen type, with CM sulfur-bearing serpentine having values of 0.1–0.2 and S2− as the dominant valency, and CIs having values of 0.9–1.0 with S6+ as the dominant valency. We suggest sulfur is structurally incorporated into serpentine as SH− partially replacing OH−, and trapped as SO42− ions, with an approximate mineral formula of (Mg Fe2+ Fe3+ Al)2-3(Si Al)2O5(OH)5-6(HS−)1-2(SO4)2−0.1-0.7. We conclude that much of the material identified in previous studies of carbonaceous chondrites as TCI-like or PCPs could be sulfur-bearing serpentine. The relatively high abundance of sulfur-bearing serpentine suggests that incorporation of sulfur into this phase was a significant part of the S-cycle in the early Solar System.
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Nov 2025
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Aquilos-CryoFIB at Diamond
Scios-Scios at Diamond
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Diamond Proposal Number(s):
[31607]
Open Access
Abstract: Hepatitis C virus (HCV) infection induces extensive rearrangements of host cytoplasmic membranes, leading to the formation of multiple membranous structures that facilitate RNA replication. Current knowledge of these membranous structures has largely relied on correlative light and electron microscopy techniques using chemical fixation and resin embedding. To overcome these limitations, cryo-preserved cells were prepared using cryo-focused ion beam (cryo-FIB) milling and cryo-ultramicrotomy. For the first time, the contents within the membranous structures have been observed in situ using cryo-electron tomography (cryo-ET) performed on lamellae (prepared via cryo-FIB) and on ultrathin sections (prepared via cryo-ultramicrotomy) from HCV subgenomic replicon-harbouring cells. Observations from 112 cryo-electron tomograms of cryo-FIB-derived samples revealed the presence of densities within the inner vesicles of a subset of single- and double-membrane vesicles, as well as within multi-vesicular bodies, which are consistent with the presence of the viral genome replication machinery. Notably, this study also presents the first direct visualization of densities within a multi-membrane vesicle observed by cryo-electron microscopy of vitreous sections. The cryo-ET methodologies established here lay the groundwork for future investigations into the architecture of the HCV replication complex, leveraging advanced computational tools for deeper structural and functional analyses.
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Nov 2025
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E02-JEM ARM 300CF
I11-High Resolution Powder Diffraction
I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[40887]
Open Access
Abstract: Owing to their vast chemical and structural flexibility, layered double hydroxides (LDHs) are among some of the most promising materials for many catalytic applications. Thermal decomposition below 700 °C leads to the formation of a complex semiamorphous mixed metal oxide (LDO). In this study, the product of calcination of aqueous miscible organic solvent-treated AMO-[Mg0.70Al0.30(OH)2](CO3)0.15·yH2O·zEtOH at 600 °C (AMO-Mg2.33Al LDO) has been investigated using a synergistic combination of high-resolution synchrotron X-ray and neutron scattering techniques, as well as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), solid-state NMR (ssNMR), and thermogravimetric analysis coupled with mass spectrometry (TGA-MS). The local and extended structure of AMO-Mg2.33Al LDO has been modeled by reciprocal and real space X-ray and neutron scattering analyses and is consistent with a modified rock salt structure consisting of octahedrally coordinated layers containing a small number of vacancies and the tetrahedrally coordinated Al3+ sites in contrast to previous reports.
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Nov 2025
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Krios I-Titan Krios I at Diamond
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Diamond Proposal Number(s):
[25452]
Open Access
Abstract: While archaeal viruses show a stunning diversity of morphologies, many bear a notable resemblance to tailed bacterial phages. This raises fundamental questions: Do all tailed viruses share a common origin and do they infect their hosts in similar ways? Answering these questions requires high-resolution structural insights, yet no complete atomic models of archaeal viruses have been available. Here, we present the near-atomic resolution structure of Haloferax tailed virus 1 (HFTV1), an archaeal virus thriving in extreme salinity. Using cryo–electron microscopy, we resolve the architecture and assembly of all structural proteins and capture conformational transitions associated with DNA ejection. Our data reveal genome spooling within the capsid and identify putative receptor-binding and catalytic sites for host recognition and infection. These findings uncover key mechanisms of archaeal virus assembly, principles of virus-host interactions, and evolutionary links connecting archaeal, bacterial, and eukaryotic viruses.
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Oct 2025
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Krios IV-Titan Krios IV at Diamond
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Diamond Proposal Number(s):
[36186]
Abstract: Ordered protein-based assemblies are increasingly desirable for materials science, but the design of new materials remains challenging and requires considerable effort. Crystal lattice contact modulation enables rapid rational design of an assortment of structurally diverse constructs with crystalline order. Targeted disruption of crystal contacts and directional growth pre-biasing allows for restricting crystal lattice growth in selected directions, resulting in lower-dimension assemblies with parent crystal structural features. Two-dimensional crystals, one-dimensional fibres, flexible ribbons, and single-walled nanotubes based on tetratricopeptide repeat proteins were constructed from reengineered 3D crystal lattices. The large library of available crystal structures provides an abundance of engineering targets, promising to make crystal contact engineering a rapid and attractive approach for the design of ordered supramolecular protein assemblies.
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Oct 2025
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Krios I-Titan Krios I at Diamond
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Andreas
Schedlbauer
,
Xu
Han
,
Wouter
Van Bakel
,
Tatsuya
Kaminishi
,
Borja
Ochoa-Lizarralde
,
Idoia
Iturrioz
,
Retina
Çapuni
,
Ransford
Parry
,
Ronny
Zegarra
,
David
Gil-Carton
,
Jorge P.
López-Alonso
,
Kristina
Barragan Sanz
,
Letizia
Brandi
,
Claudio O.
Gualerzi
,
Paola
Fucini
,
Sean R.
Connell
Diamond Proposal Number(s):
[17171, 31586]
Open Access
Abstract: The initiation phase is the rate-limiting step of protein synthesis (translation) and is finely regulated, making it an important drug target. In bacteria, initiation is guided by three initiation factors and involves positioning the start site on the messenger RNA within the P-site on the small ribosomal subunit (30S), where it is decoded by the initiator fMet–tRNA. This process can be efficiently inhibited by GE81112, a natural hydrophilic, noncyclic, nonribosomal tetrapeptide. It is found in nature in three structural variants (A, B, and B1 with molecular masses of 643–658 Da). Previous biochemical and structural characterization of GE81112 indicates that the primary mechanism of action of this antibiotic is to (i) prevent the initiator fMet–tRNA from binding correctly to the P-site and (ii) block conformational rearrangements in initiation factor IF3, resulting in an unlocked 30S preIC state. In this study, using cryo-EM, we have determined the binding site of GE81112 in initiation complexes (3.2–3.7 Å) and on empty ribosomes (2.09 Å). This binding site is within the mRNA channel but remote from the binding site of the initiation factors and initiator fMet–tRNA. This suggests that it acts allosterically to prevent the initiator fMet–tRNA from being locked into place. The binding mode is consistent with previous biochemical studies and recent work identifying the key pharmacophores of GE81112.
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Oct 2025
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B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS
B18-Core EXAFS
E02-JEM ARM 300CF
I11-High Resolution Powder Diffraction
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Mengqi
Duan
,
Shuai
Guo
,
Wentian
Niu
,
Hangjuan
Ren
,
Thomas
Dittrich
,
Dongpei
Ye
,
Lucy
Saunders
,
Sarah
Day
,
Veronica
Celorrio
,
Diego
Gianolio
,
Peixi
Cong
,
Robert S.
Weatherup
,
Robert
Taylor
,
Songhua
Cai
,
Yiyang
Li
,
Shik Chi Edman
Tsang
Diamond Proposal Number(s):
[35749, 35750, 35961, 37117]
Open Access
Abstract: Two-dimensional layered perovskite oxides have emerged as promising photocatalysts for solar-driven hydrogen evolution. Although doping has been widely employed to enhance photocatalytic performance, its role in modulating the electronic structure and the local chemical environment of these materials remains poorly understood. Here in this study, we investigate the codoping of Rh and La into exfoliated nanosheets of the Dion–Jacobson perovskite KCa2Nb3O10 to enhance photocatalytic hydrogen evolution reaction (HER) activity. A substantial increase in H2 evolution rate, from 12.3 to 69.0 μmol h–1, was achieved at an optimal doping level of 0.2 wt % Rh and 1.3 wt % La. Comprehensive structural and spectroscopic analyses, including synchrotron techniques and high-resolution microscopy, revealed that Rh3+ substitutes Nb5+ to introduce shallow 4d acceptor states that mediate charge separation, while La3+ substitutes Ca2+, compensates for aliovalent charge imbalance, and modulates local lattice distortions and oxygen vacancy formation. This codoping strategy enhances charge carrier lifetime and separation efficiency through a trap-mediated mechanism. The observed volcano-shaped activity trend highlights a narrow compositional window, where electronic and structural factors are optimally balanced. These findings establish a mechanistic foundation for defect engineering in layered perovskites and offer a pathway for the rational design of photocatalysts.
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Oct 2025
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Krios IV-Titan Krios IV at Diamond
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Diamond Proposal Number(s):
[34172]
Open Access
Abstract: Plasmodium falciparum is a eukaryotic pathogen responsible for the majority of malaria-related fatalities. Plasmodium belongs to the phylum Apicomplexa and, like most members of this phylum, contains a non-photosynthetic plastid called the apicoplast. The apicoplast has its own genome, replicated by a dedicated replisome. Unlike other cellular replisomes, the apicoplast replisome uses a single DNA polymerase (apPol). This suggests that apPol can multitask and catalyse both replicative and lesion bypass synthesis. Replicative synthesis relies on a restrictive active site for high accuracy while lesion bypass typically requires an open active site. This raises the question: how does apPol combine the structural features of multiple DNA polymerases in a single protein? Using single-particle electron cryomicroscopy (cryoEM), we have solved the structures of apPol bound to its undamaged DNA and nucleotide substrates in five pre-chemistry conformational states. We found that apPol can accommodate a nascent base pair with the fingers in an open configuration, which might facilitate the lesion bypass activity. In the fingers-open state, we identified a nascent base pair checkpoint that preferentially selects Watson–Crick base pairs, an essential requirement for replicative synthesis. Taken together, these structural features might explain how apPol balances replicative and lesion bypass synthesis.
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Oct 2025
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Krios II-Titan Krios II at Diamond
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Diamond Proposal Number(s):
[15997]
Open Access
Abstract: High-resolution structural studies have mainly focused on two out of the six adenovirus genera: mastadenoviruses and atadenoviruses. Here we report the high-resolution structure of an aviadenovirus, the poultry pathogen fowl adenovirus serotype 4 (FAdV-C4). FAdV-C4 virions are highly thermostable, despite lacking minor coat and core proteins shown to stabilize the mast- and atadenovirus particles, having no genus-specific cementing proteins, and packaging a 25% longer genome. Unique structural features of the FAdV-C4 hexon include a large insertion at the trimer equatorial region, and a long N-terminal tail. Protein IIIa conformation is closer to atadenoviruses than to mastadenoviruses, while protein VIII diverges from all previously reported structures. We interpret these differences in light of adenovirus evolution. Finally, we discuss the possible role of core composition in determining capsid stability properties. These results enlarge our view on the structural diversity of adenoviruses, and provide useful information to counteract fowl pathogens or use non-human adenoviruses as vectors.
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Oct 2025
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Krios III-Titan Krios III at Diamond
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Giovanni
Consoli
,
Fiazall
Tufail
,
Ho Fong
Leong
,
Stefania
Viola
,
Geoffry A.
Davis
,
Nicholas
Rew
,
Daniel
Medranda
,
Michael
Hofer
,
Paul
Simpson
,
Marco
Sandrin
,
Benoit
Chachuat
,
Jenny
Nelson
,
Thomas
Renger
,
James W.
Murray
,
Andrea
Fantuzzi
,
A. William
Rutherford
Diamond Proposal Number(s):
[25127]
Abstract: The discovery of chlorophyll f-containing photosystems, with their long-wavelength photochemistry, represented a distinct, low-energy paradigm for oxygenic photosynthesis. Structural studies on chlorophyll f-containing photosystem I could identify some chlorophylls f sites, but none among the photochemically active pigments and concluded that chlorophyll f plays no photochemical role. Here, we report two cryo-EM structures of far-red PSI from Chroococcidiopsis thermalis PCC 7203, allowing the assignment of eight chlorophylls f molecules, including the redox active A-1B. Simulations of absorption difference spectra induced by charge separation indicate that the experimental spectra can be reproduced only by considering the presence of a chlorophyll f at the A-1B site. The chlorophyll f locations, wavelength assignments, and conserved far-red-specific residues provide functional insights for efficient use of long wavelength photons.
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Oct 2025
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