I03-Macromolecular Crystallography
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Elisa
Peirano
,
Laura
O'Regan
,
Philip
Harrer
,
Ivana
Dzinovic
,
Magda S.
Chegkazi
,
Petra
Havrankova
,
Theresa
Brunet
,
Rossella
Capolino
,
Claudia
Cesario
,
Stefania
Ferro
,
Eva
Hammar
,
Russia
Hà-Vinh Leuchter
,
Elisabetta
Indelicato
,
Maureen
Jacob
,
Lukas
Kunc
,
Henri
Margot
,
Oriano
Marin
,
Maria
Mazurkiewicz-Bełdzińska
,
Niccolò E.
Mencacci
,
Antonio
Novelli
,
Laura
Orec
,
Michael
Poschmann
,
Alexandra
Sitzberger
,
Ugo
Sorrentino
,
Melanie
Spanjaard
,
Matias
Wagner
,
Magdalena
Krygier
,
Sylvia
Boesch
,
Jan
Necpal
,
Matej
Skorvanek
,
Donald L.
Gilbert
,
Robert
Jech
,
Mark
Dodding
,
Roberto A.
Steiner
,
Michael
Zech
Open Access
Abstract: Background: Although de novo causation in dystonia is widely acknowledged, there have been only a few trio-sequencing analyses in this field. We sought to prioritise de novo variants in dystonia and characterise the clinical and molecular features associated with the top gene candidate identified after genomic matchmaking.
Methods: We (re)assessed exome-sequencing data for de novo variants in genes with strong mutational constraint in a sample of 257 dystonia trios. Via data sharing, we collected information on individuals with variants in KLC1, encoding a subunit of the axonal-transport motor protein kinesin-1. Biophysical, biochemical, and functional studies, including differential scanning fluorimetry, X-ray crystallography, fluorescence-polarisation measurements, and immunoprecipitation from cells were performed for representative KLC1 variants. Findings: Missense and loss-of-function de novo variants in constrained genes without implication in autosomal dominant or X-linked conditions were found in 11.7% (30/257) of cases with dystonia. We then ascertained 7 unrelated patients with movement and neurodevelopmental disorders who harboured distinct, predicted deleterious de novo KLC1 missense variants. These variants clustered within the cargo adaptor-binding tetratricopeptide repeat domain and 3 variants mapped to an identical amino-acid position. Highly similar infantile-onset dystonic-spastic phenotypes were observed in the subjects with the recurrently affected residue. For all functionally tested variants, we observed changes in KLC1 stability and/or altered binding behaviour to known kinesin-1 interactors, such as JIP3, previously associated with dystonia and neurodevelopmental impairment. Interpretation: Our research supports the existence of a kinesinopathy linked to KLC1, featuring phenotypic overlap with diseases related to mutational defects of key interactors of KLC1. The full dystonia de-novo variant compendium is reported as a resource for additional disease-gene discovery.
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Jul 2026
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I24-Microfocus Macromolecular Crystallography
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Rachel
Bolton
,
Moritz M.
Machelett
,
Jack
Stubbs
,
Danny
Axford
,
Nicolas
Caramello
,
Lucrezia
Catapano
,
Martin
Maly
,
Matthew J.
Rodrigues
,
Charlotte
Cordery
,
Graham J.
Tizzard
,
Fraser
Macmillan
,
Sylvain
Engilberge
,
David
Von Stetten
,
Takehiko
Tosha
,
Hiroshi
Sugimoto
,
Jonathan A. R.
Worrall
,
Jeremy S.
Webb
,
Mike
Zubkov
,
Simon
Coles
,
Eric
Mathieu
,
Roberto A.
Steiner
,
Garib
Murshudov
,
Tobias E.
Schrader
,
Allen M.
Orville
,
Antoine
Royant
,
Gwyndaf
Evans
,
Michael A.
Hough
,
Robin L.
Owen
,
Ivo
Tews
Diamond Proposal Number(s):
[15722, 14493, 23570]
Open Access
Abstract: The marine cyanobacterium Prochlorococcus is a main contributor to global photosynthesis, whilst being limited by iron availability. Cyanobacterial genomes generally encode two different types of FutA iron-binding proteins: periplasmic FutA2 ABC transporter subunits bind Fe(III), while cytosolic FutA1 binds Fe(II). Owing to their small size and their economized genome Prochlorococcus ecotypes typically possess a single futA gene. How the encoded FutA protein might bind different Fe oxidation states was previously unknown. Here, we use structural biology techniques at room temperature to probe the dynamic behavior of FutA. Neutron diffraction confirmed four negatively charged tyrosinates, that together with a neutral water molecule coordinate iron in trigonal bipyramidal geometry. Positioning of the positively charged Arg103 side chain in the second coordination shell yields an overall charge-neutral Fe(III) binding state in structures determined by neutron diffraction and serial femtosecond crystallography. Conventional rotation X-ray crystallography using a home source revealed X-ray-induced photoreduction of the iron center with observation of the Fe(II) binding state; here, an additional positioning of the Arg203 side chain in the second coordination shell maintained an overall charge neutral Fe(II) binding site. Dose series using serial synchrotron crystallography and an XFEL X-ray pump–probe approach capture the transition between Fe(III) and Fe(II) states, revealing how Arg203 operates as a switch to accommodate the different iron oxidation states. This switching ability of the Prochlorococcus FutA protein may reflect ecological adaptation by genome streamlining and loss of specialized FutA proteins.
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Mar 2024
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I02-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
I24-Microfocus Macromolecular Crystallography
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Open Access
Abstract: Protein fold adaptation to novel enzymatic reactions is a fundamental evolutionary process. Cofactor-independent oxygenases degrading N-heteroaromatic substrates belong to the α/β-hydrolase (ABH) fold superfamily that typically does not catalyze oxygenation reactions. Here, we have integrated crystallographic analyses under normoxic and hyperoxic conditions with molecular dynamics and quantum mechanical calculations to investigate its prototypic 1-H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (HOD) member. O2 localization to the “oxyanion hole”, where catalysis occurs, is an unfavorable event and the direct competition between dioxygen and water for this site is modulated by the “nucleophilic elbow” residue. A hydrophobic pocket that overlaps with the organic substrate binding site can act as a proximal dioxygen reservoir. Freeze-trap pressurization allowed the structure of the ternary complex with a substrate analogue and O2 bound at the oxyanion hole to be determined. Theoretical calculations reveal that O2 orientation is coupled to the charge of the bound organic ligand. When 1-H-3-hydroxy-4-oxoquinaldine is uncharged, O2 binds with its molecular axis along the ligand's C2–C4 direction in full agreement with the crystal structure. Substrate activation triggered by deprotonation of its 3-OH group by the His-Asp dyad, rotates O2 by approximately 60°. This geometry maximizes the charge transfer between the substrate and O2, thus weakening the double bond of the latter. Electron density transfer to the O2(π*) orbital promotes the formation of the peroxide intermediate via intersystem crossing that is rate-determining. Our work provides a detailed picture of how evolution has repurposed the ABH-fold architecture and its simple catalytic machinery to accomplish metal-independent oxygenation.
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Oct 2023
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I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Giulia
Mori
,
Anastasia
Liuzzi
,
Luca
Ronda
,
Michele
Di Palma
,
Magda S.
Chegkazi
,
Soi
Bui
,
Mitla
Garcia-Maya
,
Jasmine
Ragazzini
,
Marco
Malatesta
,
Emanuele
Della Monica
,
Claudio
Rivetti
,
Parker B.
Antin
,
Stefano
Bettati
,
Roberto A.
Steiner
,
Riccardo
Percudani
Open Access
Abstract: Uric acid is the main means of nitrogen excretion in uricotelic vertebrates (birds and reptiles) and the end product of purine catabolism in humans and a few other mammals. While uricase is inactivated in mammals unable to degrade urate, the presence of orthologous genes without inactivating mutations in avian and reptilian genomes is unexplained. Here we show that the Gallus gallus gene we name cysteine-rich urate oxidase (CRUOX) encodes a functional protein representing a unique case of cysteine enrichment in the evolution of vertebrate orthologous genes. CRUOX retains the ability to catalyze urate oxidation to hydrogen peroxide and 5-hydroxyisourate (HIU), albeit with a 100-fold reduced efficiency. However, differently from all uricases hitherto characterized, it can also facilitate urate regeneration from HIU, a catalytic property that we propose depends on its enrichment in cysteine residues. X-ray structural analysis highlights differences in the active site compared to known orthologs and suggests a mechanism for cysteine-mediated self-aggregation under H2O2-oxidative conditions. Cysteine enrichment was concurrent with the transition to uricotelism and a shift in gene expression from the liver to the skin where CRUOX is co-expressed with β-keratins. Therefore, the loss of urate degradation in amniotes has followed opposite evolutionary trajectories: while uricase has been eliminated by pseudogenization in some mammals, it has been repurposed as a redox-sensitive enzyme in the reptilian skin.
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Sep 2023
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Jon
Agirre
,
Mihaela
Atanasova
,
Haroldas
Bagdonas
,
Charles B.
Ballard
,
Arnaud
Basle
,
James
Beilsten-Edmands
,
Rafael J.
Borges
,
David G.
Brown
,
J. Javier
Burgos-Marmol
,
John M.
Berrisford
,
Paul S.
Bond
,
Iracema
Caballero
,
Lucrezia
Catapano
,
Grzegorz
Chojnowski
,
Atlanta G.
Cook
,
Kevin D.
Cowtan
,
Tristan I.
Croll
,
Judit É.
Debreczeni
,
Nicholas E.
Devenish
,
Eleanor J.
Dodson
,
Tarik R.
Drevon
,
Paul
Emsley
,
Gwyndaf
Evans
,
Phil R.
Evans
,
Maria
Fando
,
James
Foadi
,
Luis
Fuentes-Montero
,
Elspeth F.
Garman
,
Markus
Gerstel
,
Richard J.
Gildea
,
Kaushik
Hatti
,
Maarten L.
Hekkelman
,
Philipp
Heuser
,
Soon Wen
Hoh
,
Michael A.
Hough
,
Huw T.
Jenkins
,
Elisabet
Jiménez
,
Robbie P.
Joosten
,
Ronan M.
Keegan
,
Nicholas
Keep
,
Eugene B.
Krissinel
,
Petr
Kolenko
,
Oleg
Kovalevskiy
,
Victor S.
Lamzin
,
David M.
Lawson
,
Andrey
Lebedev
,
Andrew G. W.
Leslie
,
Bernhard
Lohkamp
,
Fei
Long
,
Martin
Maly
,
Airlie
Mccoy
,
Stuart J.
Mcnicholas
,
Ana
Medina
,
Claudia
Millán
,
James W.
Murray
,
Garib N.
Murshudov
,
Robert A.
Nicholls
,
Martin E. M.
Noble
,
Robert
Oeffner
,
Navraj S.
Pannu
,
James M.
Parkhurst
,
Nicholas
Pearce
,
Joana
Pereira
,
Anastassis
Perrakis
,
Harold R.
Powell
,
Randy J.
Read
,
Daniel J.
Rigden
,
William
Rochira
,
Massimo
Sammito
,
Filomeno
Sanchez Rodriguez
,
George M.
Sheldrick
,
Kathryn L.
Shelley
,
Felix
Simkovic
,
Adam J.
Simpkin
,
Pavol
Skubak
,
Egor
Sobolev
,
Roberto A.
Steiner
,
Kyle
Stevenson
,
Ivo
Tews
,
Jens M. H.
Thomas
,
Andrea
Thorn
,
Josep Triviño
Valls
,
Ville
Uski
,
Isabel
Uson
,
Alexei
Vagin
,
Sameer
Velankar
,
Melanie
Vollmar
,
Helen
Walden
,
David
Waterman
,
Keith S.
Wilson
,
Martyn
Winn
,
Graeme
Winter
,
Marcin
Wojdyr
,
Keitaro
Yamashita
Open Access
Abstract: The Collaborative Computational Project No. 4 (CCP4) is a UK-led international collective with a mission to develop, test, distribute and promote software for macromolecular crystallography. The CCP4 suite is a multiplatform collection of programs brought together by familiar execution routines, a set of common libraries and graphical interfaces. The CCP4 suite has experienced several considerable changes since its last reference article, involving new infrastructure, original programs and graphical interfaces. This article, which is intended as a general literature citation for the use of the CCP4 software suite in structure determination, will guide the reader through such transformations, offering a general overview of the new features and outlining future developments. As such, it aims to highlight the individual programs that comprise the suite and to provide the latest references to them for perusal by crystallographers around the world.
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Jun 2023
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I03-Macromolecular Crystallography
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Abstract: Synthetic peptides are attractive candidates to manipulate protein-protein interactions inside the cell as they mimic natural interactions to compete for binding. However, protein-peptide interactions are often dynamic and weak. A challenge is to design peptides that make improved interactions with the target. Here, we devise a fragment-linking strategy—“mash-up” design—to deliver a high-affinity ligand, KinTag, for the kinesin-1 motor. Using structural insights from natural micromolar-affinity cargo-adaptor ligands, we have identified and combined key binding features in a single, high-affinity ligand. An X-ray crystal structure demonstrates interactions as designed and reveals only a modest increase in interface area. Moreover, when genetically encoded, KinTag promotes transport of lysosomes with higher efficiency than natural sequences, revealing a direct link between motor-adaptor binding affinity and organelle transport. Together, these data demonstrate a fragment-linking strategy for peptide design and its application in a synthetic motor ligand to direct cellular cargo transport.
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Apr 2021
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I04-Macromolecular Crystallography
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Open Access
Abstract: The light chains (KLCs) of the heterotetrameric microtubule motor kinesin-1, that bind to cargo adaptor proteins and regulate its activity, have a capacity to recognize short peptides via their tetratricopeptide repeat domains (KLCTPR). Here, using X-ray crystallography, we show how kinesin-1 recognizes a novel class of adaptor motifs that we call ‘Y-acidic’ (tyrosine flanked by acidic residues), in a KLC-isoform specific manner. Binding specificities of Y-acidic motifs (present in JIP1 and in TorsinA) to KLC1TPR are distinct from those utilized for the recognition of W-acidic motifs found in adaptors that are KLC- isoform non-selective. However, a partial overlap on their receptor binding sites implies that adaptors relying on Y-acidic and W-acidic motifs must act independently. We propose a model to explain why these two classes of motifs that bind to the concave surface of KLCTPR with similar low micromolar affinity can exhibit different capacities to promote kinesin-1 activity.
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Oct 2018
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I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Open Access
Abstract: The sarcomeric cytoskeleton is a network of modular proteins that integrate mechanical and signaling roles. Obscurin, or its homolog obscurin-like-1, bridges the giant ruler titin and the myosin crosslinker myomesin at the M-band. Yet, the molecular mechanisms underlying the physical obscurin(-like-1):myomesin connection, important for mechanical integrity of the M-band, remained elusive. Here, using a combination of structural, cellular, and single-molecule force spectroscopy techniques, we decode the architectural and functional determinants defining the obscurin(-like-1):myomesin complex. The crystal structure reveals a trans-complementation mechanism whereby an incomplete immunoglobulin-like domain assimilates an isoform-specific myomesin interdomain sequence. Crucially, this unconventional architecture provides mechanical stability up to forces of ∼135 pN. A cellular competition assay in neonatal rat cardiomyocytes validates the complex and provides the rationale for the isoform specificity of the interaction. Altogether, our results reveal a novel binding strategy in sarcomere assembly, which might have implications on muscle nanomechanics and overall M-band organization.
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Jan 2017
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I24-Microfocus Macromolecular Crystallography
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Abstract: The light chains (KLCs) of the microtubule motor kinesin-1 bind cargoes and regulate its activity. Through their tetratricopeptide repeat domain (KLCTPR), they can recognize short linear peptide motifs found in many cargo proteins characterized by a central tryptophan flanked by aspartic/glutamic acid residues (W-acidic). Using a fluorescence resonance energy transfer biosensor in combination with X-ray crystallographic, biochemical, and biophysical approaches, we describe how an intramolecular interaction between the KLC2TPR domain and a conserved peptide motif within an unstructured region of the molecule, partly occludes the W-acidic binding site on the TPR domain. Cargo binding displaces this interaction, effecting a global conformational change in KLCs resulting in a more extended conformation. Thus, like the motor-bearing kinesin heavy chains, KLCs exist in a dynamic conformational state that is regulated by self-interaction and cargo binding. We propose a model by which, via this molecular switch, W-acidic cargo binding regulates the activity of the holoenzyme.
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Feb 2016
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
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C. X.
Santos
,
A. D.
Hafstad
,
M.
Beretta
,
M.
Zhang
,
C.
Molenaar
,
J.
Kopec
,
D.
Fotinou
,
T. V.
Murray
,
A. M.
Cobb
,
D.
Martin
,
M.
Zeh Silva
,
N.
Anilkumar
,
K.
Schroder
,
C. M.
Shanahan
,
A. C.
Brewer
,
R. P.
Brandes
,
E.
Blanc
,
M.
Parsons
,
V.
Belousov
,
R.
Cammack
,
R. C.
Hider
,
R. A.
Steiner
,
A. M.
Shah
Diamond Proposal Number(s):
[7656]
Open Access
Abstract: Phosphorylation of translation initiation factor 2α (eIF2α) attenuates global protein synthesis but enhances translation of activating transcription factor 4 (ATF4) and is a crucial evolutionarily conserved adaptive pathway during cellular stresses. The serine–threonine protein phosphatase 1 (PP1) deactivates this pathway whereas prolonging eIF2α phosphorylation enhances cell survival. Here, we show that the reactive oxygen species‐generating NADPH oxidase‐4 (Nox4) is induced downstream of ATF4, binds to a PP1‐targeting subunit GADD34 at the endoplasmic reticulum, and inhibits PP1 activity to increase eIF2α phosphorylation and ATF4 levels. Other PP1 targets distant from the endoplasmic reticulum are unaffected, indicating a spatially confined inhibition of the phosphatase. PP1 inhibition involves metal center oxidation rather than the thiol oxidation that underlies redox inhibition of protein tyrosine phosphatases. We show that this Nox4‐regulated pathway robustly enhances cell survival and has a physiologic role in heart ischemia–reperfusion and acute kidney injury. This work uncovers a novel redox signaling pathway, involving Nox4–GADD34 interaction and a targeted oxidative inactivation of the PP1 metal center, that sustains eIF2α phosphorylation to protect tissues under stress.
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Jan 2016
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