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View article: Robust error calibration for serial crystallography
Robust error calibration for serial crystallography Open
Serial crystallography is an important technique with unique abilities to resolve enzymatic transition states, minimize radiation damage to sensitive metalloenzymes, and perform de novo structure determination from micron sized crystals. T…
View article: Spatially resolved anomalous dispersion method for determination of site-specific oxidation states in metalloenzymes at XFEL sources
Spatially resolved anomalous dispersion method for determination of site-specific oxidation states in metalloenzymes at XFEL sources Open
Catalysis by metalloenzymes is controlled by precise movement of protons and electrons at active sites which are often coordinated with ligand binding, side-chain movement, or larger protein conformational changes. We seek to understand th…
View article: Attosecond inner-shell lasing at ångström wavelengths
Attosecond inner-shell lasing at ångström wavelengths Open
Since the invention of the laser, nonlinear effects such as filamentation1, Rabi cycling2,3 and collective emission4 have been explored in the optical regime, leading to a wide range of scientific and industrial applications5-8. X-ray free…
View article: Serial-femtosecond crystallography reveals how a phytochrome variant couples chromophore and protein structural changes
Serial-femtosecond crystallography reveals how a phytochrome variant couples chromophore and protein structural changes Open
The photoreaction and commensurate structural changes of a chromophore within biological photoreceptors elicit conformational transitions of the protein promoting the switch between deactivated and activated states. We investigated how thi…
View article: Why the Electron Chooses One of Two Symmetry-Related Paths in the Type II Bacterial Photosynthetic Reaction Centers
Why the Electron Chooses One of Two Symmetry-Related Paths in the Type II Bacterial Photosynthetic Reaction Centers Open
Photosynthetic reaction centers carry out a series of electron and proton transfer reactions that convert the energy of light into high energy reduced products and add to the proton gradient. All photosynthetic reaction centers (Photosyste…
View article: Robust error calibration for serial crystallography
Robust error calibration for serial crystallography Open
Serial crystallography is an important technique with unique abilities to resolve enzymatic transition states, minimize radiation damage to sensitive metalloenzymes and perform de novo structure determination from micrometre-sized crystals…
View article: Structure of active methyl-CoM reductase, Earth’s main methane producer
Structure of active methyl-CoM reductase, Earth’s main methane producer Open
Summary Our work reveals the structure of the active state of Methyl-Coenzyme M Reductase (MCR), the key and rate-limiting enzyme in biological methane formation. We find large differences between the active Ni(I) and inactive Ni(II) prote…
View article: Single-Cell Epigenomics Uncovers Heterochromatin Instability and Transcription Factor Dysfunction during Mouse Brain Aging
Single-Cell Epigenomics Uncovers Heterochromatin Instability and Transcription Factor Dysfunction during Mouse Brain Aging Open
Summary The mechanisms regulating transcriptional changes in brain aging remain poorly understood. Here, we use single-cell epigenomics to profile chromatin accessibility and gene expression across eight brain regions in the mouse brain at…
View article: X-ray Absorption Spectroscopy of Dilute Metalloenzymes at X-ray Free-Electron Lasers in a Shot-by-Shot Mode
X-ray Absorption Spectroscopy of Dilute Metalloenzymes at X-ray Free-Electron Lasers in a Shot-by-Shot Mode Open
X-ray absorption spectroscopy (XAS) of 3d transition metals provides important electronic structure information for many fields. However, X-ray-induced radiation damage under physiological temperature has prevented using this method to stu…
View article: Structural changes in Photosystem II using time-resolved X-ray free-electron (XFEL) crystallography and crystalline molecular dynamics.
Structural changes in Photosystem II using time-resolved X-ray free-electron (XFEL) crystallography and crystalline molecular dynamics. Open
The water oxidation complex (Mn4CaO5 complex) in Photosystem II is the catalyst for the transformation of two water molecules to molecular oxygen, releasing four electrons and four protons in the process. Starting from the ground state, th…
View article: Towards the spatial resolution of photosystem II charge states from XFEL diffraction data
Towards the spatial resolution of photosystem II charge states from XFEL diffraction data Open
Photosynthesis provides most of the bio-available energy and oxygen to our planet. Yet, while several other mechanisms in oxygenic and anoxygenic photosynthesis have been thoroughly investigated, the core water-splitting reaction of photos…
View article: Probing soft X-ray induced photoreduction of a model Mn-complex at cryogenic conditions
Probing soft X-ray induced photoreduction of a model Mn-complex at cryogenic conditions Open
Soft X-ray absorption spectroscopy of first row transition elements at their respective L -edges provides important information about the oxidation and spin states of the metal centers. However, the associated sample damage in radiation-se…
View article: Tribute to Kenneth Sauer (1931–2022): a mentor, a role-model, and an inspiration to all in the field of photosynthesis
Tribute to Kenneth Sauer (1931–2022): a mentor, a role-model, and an inspiration to all in the field of photosynthesis Open
Kenneth (Ken) Sauer was a mainstay of research in photosynthesis at the University of California, Berkeley and the Lawrence Berkeley National Laboratory (LBNL) for more than 50 years. Ken will be remembered by his colleagues, and other wor…
View article: Mental health benefit uptake of women before and during the perinatal period in Austria
Mental health benefit uptake of women before and during the perinatal period in Austria Open
One in five women may experience a perinatal mental illness (PMI) during pregnancy and up to one year after giving birth, during the so-called perinatal period. Although there is strong evidence that this can have a negative effect on the …
View article: Attosecond Inner-Shell Lasing at Angstrom Wavelengths
Attosecond Inner-Shell Lasing at Angstrom Wavelengths Open
Since the invention of the laser nonlinear effects such as filamentation, Rabi-cycling and collective emission have been explored in the optical regime leading to a wide range of scientific and industrial applications. X-ray free electron …
View article: Light-Induced Charge Separation in Photosystem I from Different Biological Species Characterized by Multifrequency Electron Paramagnetic Resonance Spectroscopy
Light-Induced Charge Separation in Photosystem I from Different Biological Species Characterized by Multifrequency Electron Paramagnetic Resonance Spectroscopy Open
Photosystem I (PSI) serves as a model system for studying fundamental processes such as electron transfer (ET) and energy conversion, which are not only central to photosynthesis but also have broader implications for bioenergy production …
View article: Lighting the way: Compelling open questions in photosynthesis research
Lighting the way: Compelling open questions in photosynthesis research Open
Photosynthesis—the conversion of energy from sunlight into chemical energy—is essential for life on Earth. Yet there is much we do not understand about photosynthetic energy conversion on a fundamental level: how it evolved and the extent …
View article: Structure Function Studies of Photosystem II Using X-Ray Free Electron Lasers
Structure Function Studies of Photosystem II Using X-Ray Free Electron Lasers Open
The structure and mechanism of the water-oxidation chemistry that occurs in photosystem II have been subjects of great interest. The advent of X-ray free electron lasers allowed the determination of structures of the stable intermediate st…
View article: Light-Induced Charge Separation in Photosystem I from Different Biological Species Characterized by Multifrequency EPR
Light-Induced Charge Separation in Photosystem I from Different Biological Species Characterized by Multifrequency EPR Open
Photosystem I (PSI) serves as a model system for studying fundamental processes such as electron transfer (ET) and energy conversion, which are not only central to photosynthesis but also have broader implications for bioenergy production …
View article: Coherences of Photoinduced Electron Spin Qubit Pair States in Photosystem I
Coherences of Photoinduced Electron Spin Qubit Pair States in Photosystem I Open
This publication presents the first comprehensive experimental study of electron spin coherences in photosynthetic reaction center proteins, specifically focusing on photosystem I (PSI). The ultrafast electron transfer in PSI generates spi…
View article: In Situ Structural Observation of a Substrate- and Peroxide-Bound High-Spin Ferric-Hydroperoxo Intermediate in the P450 Enzyme CYP121
In Situ Structural Observation of a Substrate- and Peroxide-Bound High-Spin Ferric-Hydroperoxo Intermediate in the P450 Enzyme CYP121 Open
The P450 enzyme CYP121 from Mycobacterium tuberculosis catalyzes a carbon-carbon (C-C) bond coupling cyclization of the dityrosine substrate containing a diketopiperazine ring, cyclo(l-tyrosine-l-tyrosine) (cYY). An unusual high-spin (S = …
View article: Seeded stimulated x-ray emission at 5.9 keV: erratum
Seeded stimulated x-ray emission at 5.9 keV: erratum Open
We recently identified two labeling-related mistakes in Optica 10 , 513 ( 2023 ) OPTIC8 2334-2536 10.1364/OPTICA.485989 . The first mistake concerns the labeling of the focus used during one scan. The second mistake concerns the labeling o…
View article: Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography
Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography Open
The water oxidation reaction in photosystem II (PS II) produces most of the molecular oxygen in the atmosphere, which sustains life on Earth, and in this process releases four electrons and four protons that drive the downstream process of…
View article: Structure of a ribonucleotide reductase R2 protein radical
Structure of a ribonucleotide reductase R2 protein radical Open
Aerobic ribonucleotide reductases (RNRs) initiate synthesis of DNA building blocks by generating a free radical within the R2 subunit; the radical is subsequently shuttled to the catalytic R1 subunit through proton-coupled electron transfe…
View article: Water Networks in Photosystem II Using Crystalline Molecular Dynamics Simulations and Room-Temperature XFEL Serial Crystallography
Water Networks in Photosystem II Using Crystalline Molecular Dynamics Simulations and Room-Temperature XFEL Serial Crystallography Open
Structural dynamics of water and its hydrogen-bonding networks play an important role in enzyme function via the transport of protons, ions, and substrates. To gain insights into these mechanisms in the water oxidation reaction in Photosys…