I24-Microfocus Macromolecular Crystallography
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Open Access
Abstract: Proof of concept of serial crystallography is carried out through the translation of samples delivered by tractor beam levitation. This is achieved using arrays of low powered transducers, focused to produce acoustic traps. Contrary to traditional Langevin Horn levitators, power requirement remains in the region of 10W, limiting the acoustic pressure on the levitated samples and hence the risk of damage to them. Automation is achieved by controlling the phase of the transducers. The traps and associated samples steadily translate with the controlled acoustic field. A translation speed of 2.8mms−1 between the nodal distance of the traps is achieved. This results in sequential delivery of sample containing droplets performed with 1.5s between each delivery. The results demonstrate the ability to capture automated measurements of diffraction from lysozyme micro-crystals. Our study points in the direction of an automated, acoustic levitation system for time-resolved crystallography.
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Dec 2022
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I24-Microfocus Macromolecular Crystallography
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James
Baxter
,
Christopher D. M.
Hutchison
,
Karim
Maghlaoui
,
Violeta
Cordon-Preciado
,
R. Marc L.
Morgan
,
Pierre
Aller
,
Agata
Butryn
,
Danny
Axford
,
Sam
Horrell
,
Robin L.
Owen
,
Selina L. S.
Storm
,
Nicholas E.
Devenish
,
Jasper J.
Van Thor
Diamond Proposal Number(s):
[17221]
Open Access
Abstract: The chromophores of reversibly switchable fluorescent proteins (rsFPs) undergo photoisomerization of both the trans and cis forms. Concurrent with cis/trans photoisomerisation, rsFPs typically become protonated on the phenolic oxygen resulting in a blue shift of the absorption. A synthetic rsFP referred to as rsEospa, derived from EosFP family, displays the same spectroscopic behavior as the GFP-like rsFP Dronpa at pH 8.4 and involves the photoconversion between nonfluorescent neutral and fluorescent anionic chromophore states. Millisecond time-resolved synchrotron serial crystallography of rsEospa at pH 8.4 shows that photoisomerization is accompanied by rearrangements of the same three residues as seen in Dronpa. However, at pH 5.5 we observe that the OFF state is identified as the cationic chromophore with additional protonation of the imidazolinone nitrogen which is concurrent with a newly formed hydrogen bond with the Glu212 carboxylate side chain. FTIR spectroscopy resolves the characteristic up-shifted carbonyl stretching frequency at 1713 cm–1 for the cationic species. Electronic spectroscopy furthermore distinguishes the cationic absorption band at 397 nm from the neutral species at pH 8.4 seen at 387 nm. The observation of photoisomerization of the cationic chromophore state demonstrates the conical intersection for the electronic configuration, where previously fluorescence was proposed to be the main decay route for states containing imidazolinone nitrogen protonation. We present the full time-resolved room-temperature X-ray crystallographic, FTIR, and UV/vis assignment and photoconversion modeling of rsEospa.
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Nov 2022
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Juliane
John
,
Oskar
Aurelius
,
Vivek
Srinivas
,
Patricia
Saura
,
In-Sik
Kim
,
Asmit
Bhowmick
,
Philipp S.
Simon
,
Medhanjali
Dasgupta
,
Cindy
Pham
,
Sheraz
Gul
,
Kyle D.
Sutherlin
,
Pierre
Aller
,
Agata
Butryn
,
Allen M.
Orville
,
Mun Hon
Cheah
,
Shigeki
Owada
,
Kensuke
Tono
,
Franklin D
Fuller
,
Alexander
Batyuk
,
Aaron S.
Brewster
,
Nicholas K.
Sauter
,
Vittal K
Yachandra
,
Junko
Yano
,
Ville R. I.
Kaila
,
Jan
Kern
,
Hugo
Lebrette
,
Martin
Högbom
Open Access
Abstract: Redox reactions are central to biochemistry and are both controlled by and induce protein structural changes. Here, we describe structural rearrangements and crosstalk within the Bacillus cereus ribonucleotide reductase R2b–NrdI complex, a di-metal carboxylate-flavoprotein system, as part of the mechanism generating the essential catalytic free radical of the enzyme. Femtosecond crystallography at an X-ray free electron laser was utilized to obtain structures at room temperature in defined redox states without suffering photoreduction. Together with density functional theory calculations, we show that the flavin is under steric strain in the R2b–NrdI protein complex, likely tuning its redox properties to promote superoxide generation. Moreover, a binding site in close vicinity to the expected flavin O2 interaction site is observed to be controlled by the redox state of the flavin and linked to the channel proposed to funnel the produced superoxide species from NrdI to the di-manganese site in protein R2b. These specific features are coupled to further structural changes around the R2b–NrdI interaction surface. The mechanistic implications for the control of reactive oxygen species and radical generation in protein R2b are discussed.
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Sep 2022
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I24-Microfocus Macromolecular Crystallography
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Richard J.
Gildea
,
James
Beilsten-Edmands
,
Danny
Axford
,
Sam
Horrell
,
Pierre
Aller
,
James
Sandy
,
Juan
Sanchez-Weatherby
,
C. David
Owen
,
Petra
Lukacik
,
Claire
Strain-Damerell
,
Robin L.
Owen
,
Martin A.
Walsh
,
Graeme
Winter
Diamond Proposal Number(s):
[26986, 27088]
Open Access
Abstract: In macromolecular crystallography, radiation damage limits the amount of data that can be collected from a single crystal. It is often necessary to merge data sets from multiple crystals; for example, small-wedge data collections from micro-crystals, in situ room-temperature data collections and data collection from membrane proteins in lipidic mesophases. Whilst the indexing and integration of individual data sets may be relatively straightforward with existing software, merging multiple data sets from small wedges presents new challenges. The identification of a consensus symmetry can be problematic, particularly in the presence of a potential indexing ambiguity. Furthermore, the presence of non-isomorphous or poor-quality data sets may reduce the overall quality of the final merged data set. To facilitate and help to optimize the scaling and merging of multiple data sets, a new program, xia2.multiplex, has been developed which takes data sets individually integrated with DIALS and performs symmetry analysis, scaling and merging of multi-crystal data sets. xia2.multiplex also performs analysis of various pathologies that typically affect multi-crystal data sets, including non-isomorphism, radiation damage and preferential orientation. After the description of a number of use cases, the benefit of xia2.multiplex is demonstrated within a wider autoprocessing framework in facilitating a multi-crystal experiment collected as part of in situ room-temperature fragment-screening experiments on the SARS-CoV-2 main protease.
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Jun 2022
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Patrick
Rabe
,
Jos J. A. G.
Kamps
,
Kyle D.
Sutherlin
,
James D. S.
Linyard
,
Pierre
Aller
,
Cindy C.
Pham
,
Mikako
Makita
,
Ian
Clifton
,
Michael A.
Mcdonough
,
Thomas M.
Leissing
,
Denis
Shutin
,
Pauline A.
Lang
,
Agata
Butryn
,
Jurgen
Brem
,
Sheraz
Gul
,
Franklin D.
Fuller
,
In-Sik
Kim
,
Mun Hon
Cheah
,
Thomas
Fransson
,
Asmit
Bhowmick
,
Iris D.
Young
,
Lee
O'Riordan
,
Aaron S.
Brewster
,
Ilaria
Pettinati
,
Margaret
Doyle
,
Yasumasa
Joti
,
Shigeki
Owada
,
Kensuke
Tono
,
Alexander
Batyuk
,
Mark S.
Hunter
,
Roberto
Alonso-Mori
,
Uwe
Bergmann
,
Robin L.
Owen
,
Nicholas K.
Sauter
,
Timothy D. W.
Claridge
,
Carol V.
Robinson
,
Vittal K.
Yachandra
,
Junko
Yano
,
Jan F.
Kern
,
Allen M.
Orville
,
Christopher J.
Schofield
Diamond Proposal Number(s):
[23459, 19458]
Open Access
Abstract: Isopenicillin N synthase (IPNS) catalyzes the unique reaction of L-δ-(α-aminoadipoyl)-L-cysteinyl-D-valine (ACV) with dioxygen giving isopenicillin N (IPN), the precursor of all natural penicillins and cephalosporins. X-ray free-electron laser studies including time-resolved crystallography and emission spectroscopy reveal how reaction of IPNS:Fe(II):ACV with dioxygen to yield an Fe(III) superoxide causes differences in active site volume and unexpected conformational changes that propagate to structurally remote regions. Combined with solution studies, the results reveal the importance of protein dynamics in regulating intermediate conformations during conversion of ACV to IPN. The results have implications for catalysis by multiple IPNS-related oxygenases, including those involved in the human hypoxic response, and highlight the power of serial femtosecond crystallography to provide insight into long-range enzyme dynamics during reactions presently impossible for nonprotein catalysts.
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Aug 2021
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I24-Microfocus Macromolecular Crystallography
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Agata
Butryn
,
Philipp S.
Simon
,
Pierre
Aller
,
Philip
Hinchliffe
,
Ramzi N.
Massad
,
Gabriel
Leen
,
Catherine L.
Tooke
,
Isabel
Bogacz
,
In-Sik
Kim
,
Asmit
Bhowmick
,
Aaron S.
Brewster
,
Nicholas E.
Devenish
,
Jurgen
Brem
,
Jos J. A. G.
Kamps
,
Pauline A.
Lang
,
Patrick
Rabe
,
Danny
Axford
,
John H.
Beale
,
Bradley
Davy
,
Ali
Ebrahim
,
Julien
Orlans
,
Selina L. S.
Storm
,
Tiankun
Zhou
,
Shigeki
Owada
,
Rie
Tanaka
,
Kensuke
Tono
,
Gwyndaf
Evans
,
Robin L.
Owen
,
Frances A.
Houle
,
Nicholas K.
Sauter
,
Christopher J.
Schofield
,
James
Spencer
,
Vittal K.
Yachandra
,
Junko
Yano
,
Jan F.
Kern
,
Allen M.
Orville
Diamond Proposal Number(s):
[19458, 25260]
Open Access
Abstract: Serial femtosecond crystallography has opened up many new opportunities in structural biology. In recent years, several approaches employing light-inducible systems have emerged to enable time-resolved experiments that reveal protein dynamics at high atomic and temporal resolutions. However, very few enzymes are light-dependent, whereas macromolecules requiring ligand diffusion into an active site are ubiquitous. In this work we present a drop-on-drop sample delivery system that enables the study of enzyme-catalyzed reactions in microcrystal slurries. The system delivers ligand solutions in bursts of multiple picoliter-sized drops on top of a larger crystal-containing drop inducing turbulent mixing and transports the mixture to the X-ray interaction region with temporal resolution. We demonstrate mixing using fluorescent dyes, numerical simulations and time-resolved serial femtosecond crystallography, which show rapid ligand diffusion through microdroplets. The drop-on-drop method has the potential to be widely applicable to serial crystallography studies, particularly of enzyme reactions with small molecule substrates.
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Jul 2021
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I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Julien
Orlans
,
Carole
Vincent-Monegat
,
Isabelle
Rahioui
,
Catherine
Sivignon
,
Agata
Butryn
,
Laurent
Soulère
,
Anna
Zaidman-Remy
,
Allen M.
Orville
,
Abdelaziz
Heddi
,
Pierre
Aller
,
Pedro
Da Silva
Diamond Proposal Number(s):
[19737, 19458, 23571]
Open Access
Abstract: Peptidoglycan recognition proteins (PGRPs) are ubiquitous among animals and play pivotal functions in insect immunity. Non-catalytic PGRPs are involved in the activation of immune pathways by binding to the peptidoglycan (PGN), whereas amidase PGRPs are capable of cleaving the PGN into non-immunogenic compounds. Drosophila PGRP-LB belongs to the amidase PGRPs and downregulates the immune deficiency (IMD) pathway by cleaving meso-2,6-diaminopimelic (meso-DAP or DAP)-type PGN. While the recognition process is well analyzed for the non-catalytic PGRPs, little is known about the enzymatic mechanism for the amidase PGRPs, despite their essential function in immune homeostasis. Here, we analyzed the specific activity of different isoforms of Drosophila PGRP-LB towards various PGN substrates to understand their specificity and role in Drosophila immunity. We show that these isoforms have similar activity towards the different compounds. To analyze the mechanism of the amidase activity, we performed site directed mutagenesis and solved the X-ray structures of wild-type Drosophila PGRP-LB and its mutants, with one of these structures presenting a protein complexed with the tracheal cytotoxin (TCT), a muropeptide derived from the PGN. Only the Y78F mutation abolished the PGN cleavage while other mutations reduced the activity solely. Together, our findings suggest the dynamic role of the residue Y78 in the amidase mechanism by nucleophilic attack through a water molecule to the carbonyl group of the amide function destabilized by Zn2+.
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May 2021
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Abstract: Macromolecular crystallography (MX) leverages the methods of physics and the language of chemistry to reveal fundamental insights into biology. Often beautifully artistic images present MX results to support profound functional hypotheses that are vital to entire life science research community. Over the past several decades, synchrotrons around the world have been the workhorses for X-ray diffraction data collection at many highly automated beamlines. The newest tools include X-ray-free electron lasers (XFELs) located at facilities in the USA, Japan, Korea, Switzerland, and Germany that deliver about nine orders of magnitude higher brightness in discrete femtosecond long pulses. At each of these facilities, new serial femtosecond crystallography (SFX) strategies exploit slurries of micron-size crystals by rapidly delivering individual crystals into the XFEL X-ray interaction region, from which one diffraction pattern is collected per crystal before it is destroyed by the intense X-ray pulse. Relatively simple adaptions to SFX methods produce time-resolved data collection strategies wherein reactions are triggered by visible light illumination or by chemical diffusion/mixing. Thus, XFELs provide new opportunities for high temporal and spatial resolution studies of systems engaged in function at physiological temperature. In this chapter, we summarize various issues related to microcrystal slurry preparation, sample delivery into the X-ray interaction region, and some emerging strategies for time-resolved SFX data collection.
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May 2021
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I24-Microfocus Macromolecular Crystallography
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Patrick
Rabe
,
John
Beale
,
Agata
Butryn
,
Pierre
Aller
,
Anna
Dirr
,
Pauline A.
Lang
,
Danny N.
Axford
,
Stephen
Carr
,
Thomas M.
Leissing
,
Michael A.
Mcdonough
,
Bradley
Davy
,
Ali
Ebrahim
,
Julien
Orlans
,
Selina L. S.
Storm
,
Allen M.
Orville
,
Christopher J.
Schofield
,
Robin L.
Owen
Diamond Proposal Number(s):
[19458]
Open Access
Abstract: Cryogenic X-ray diffraction is a powerful tool for crystallographic studies on enzymes including oxygenases and oxidases. Amongst the benefits that cryo-conditions (usually employing a nitrogen cryo-stream at 100 K) enable, is data collection of dioxygen-sensitive samples. Although not strictly anaerobic, at low temperatures the vitreous ice conditions severely restrict O2 diffusion into and/or through the protein crystal. Cryo-conditions limit chemical reactivity, including reactions that require significant conformational changes. By contrast, data collection at room temperature imposes fewer restrictions on diffusion and reactivity; room-temperature serial methods are thus becoming common at synchrotrons and XFELs. However, maintaining an anaerobic environment for dioxygen-dependent enzymes has not been explored for serial room-temperature data collection at synchrotron light sources. This work describes a methodology that employs an adaptation of the `sheet-on-sheet' sample mount, which is suitable for the low-dose room-temperature data collection of anaerobic samples at synchrotron light sources. The method is characterized by easy sample preparation in an anaerobic glovebox, gentle handling of crystals, low sample consumption and preservation of a localized anaerobic environment over the timescale of the experiment (<5 min). The utility of the method is highlighted by studies with three X-ray-radiation-sensitive Fe(II)-containing model enzymes: the 2-oxoglutarate-dependent L-arginine hydroxylase VioC and the DNA repair enzyme AlkB, as well as the oxidase isopenicillin N synthase (IPNS), which is involved in the biosynthesis of all penicillin and cephalosporin antibiotics.
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Sep 2020
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I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Diamond Proposal Number(s):
[14449, 16818]
Open Access
Abstract: In this article, a new approach to experimental phasing for macromolecular crystallography (MX) at synchrotrons is introduced and described for the first time. It makes use of automated robotics applied to a multi-crystal framework in which human intervention is reduced to a minimum. Hundreds of samples are automatically soaked in heavy-atom solutions, using a Labcyte Inc. Echo 550 Liquid Handler, in a highly controlled and optimized fashion in order to generate derivatized and isomorphous crystals. Partial data sets obtained on MX beamlines using an in situ setup for data collection are processed with the aim of producing good-quality anomalous signal leading to successful experimental phasing.
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Aug 2020
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