A new structural insight into differential interaction of cyanobacterial and plant ferredoxins with nitrite reductase as revealed by NMR and X-ray crystallographic studies

2012 ◽  
Vol 151 (5) ◽  
pp. 483-492 ◽  
Author(s):  
Yukiko Sakakibara ◽  
Hitoshi Kimura ◽  
Akira Iwamura ◽  
Takashi Saitoh ◽  
Takahisa Ikegami ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
X Ray ◽  
Differential Interaction ◽  
Structural Insight ◽  
Insight Into

scholarly journals X-Ray Structure of 12-Oxophytodienoate Reductase 1 Provides Structural Insight into Substrate Binding and Specificity within the Family of OYE

Structure ◽  
2001 ◽  
Vol 9 (5) ◽  
pp. 419-429 ◽  
Author(s):  
Constanze Breithaupt ◽  
Jochen Strassner ◽  
Ulrike Breitinger ◽  
Robert Huber ◽  
Peter Macheroux ◽  
...  
Keyword(s):  
Substrate Binding ◽  
X Ray ◽  
The Family ◽  
Structural Insight ◽  
Insight Into

scholarly journals X-ray Raman scattering for bulk chemical and structural insight into green carbon

2020 ◽  
Vol 22 (33) ◽  
pp. 18435-18446
Author(s):  
Luke J. R. Higgins ◽  
Christoph J. Sahle ◽  
Mahalingam Balasubramanian ◽  
Bhoopesh Mishra
Keyword(s):  
Raman Scattering ◽  
X Ray ◽  
Bulk Chemical ◽  
Structural Insight ◽  
Insight Into ◽  
Absorption Edges

X-ray Raman scattering (XRS) spectroscopy provides access to element-specific core photo-absorption edges of low Z-elements (e.g. K-edges of C, N, O), using hard X-ray photons enabling bulk and in situ study of green carbons.

scholarly journals Structural Insight into the Activation Mechanism of Human Pancreatic Prophospholipase A2

2009 ◽  
Vol 284 (24) ◽  
pp. 16659-16666 ◽  
Author(s):  
Wei Xu ◽  
Lina Yi ◽  
Yumei Feng ◽  
Ling Chen ◽  
Jinsong Liu
Keyword(s):  
Phospholipase A2 ◽  
Catalytic Triad ◽  
Activation Mechanism ◽  
X Ray ◽  
Pancreatic Phospholipase ◽  
Pancreatic Phospholipase A2 ◽  
Obesity And Diabetes ◽  
Membrane Bound ◽  
Structural Insight ◽  
Insight Into

Pancreatic phospholipase A2 (phospholipase A2 group 1B, G1B) belongs to the superfamily of secreted phospholipase A2 (PLA2) enzymes. G1B has been proposed to be a potential target for diseases such as hypertension, obesity, and diabetes. Human pancreatic prophospholipase A2 (pro-hG1B) is activated by cleavage of the first seven-residue propeptide (phospholipase A2 propeptide, PROP). However, questions still remain on the mode of action for pro-hG1B. In this work, we expressed pro-hG1B in Pichia pastoris and determined the crystal structure at 1.55-Å resolution. The x-ray structure demonstrates that pro-hG1B forms a trimer. In addition, PROP occupies the catalytic cavity and can be self-cleaved at 37 °C. A new membrane-bound surface and activation mechanism are proposed based on the trimeric model of pro-hG1B. We also propose a new autoproteolytic mechanism for pro-hG1B by the reaction triad Asp49-Arg0-Ser(-2) that is similar to the serine protease catalytic triad.

scholarly journals Structural studies on dehydroshikimate dehydratase

2014 ◽  
Vol 70 (a1) ◽  
pp. C475-C475
Author(s):  
James Peek ◽  
Dinesh Christendat
Keyword(s):  
Sole Carbon Source ◽  
Catalytic Mechanism ◽  
Substrate Recognition ◽  
Structural Studies ◽  
Sugar Phosphate ◽  
X Ray ◽  
Structural Insight ◽  
Functional Relevance ◽  
Insight Into

The soil bacterium, Pseudomonas putida, is capable of using the alicyclic compound quinate as a sole carbon source. During this process, quinate is converted to 3-dehydroshikimate, which subsequently undergoes a dehydration to form protocatechuate. The latter transformation is performed by the enzyme dehydroshikimate dehydratase (DSD). We have recombinantly produced DSD from P. putida and are currently performing x-ray crystallographic studies on the enzyme to gain structural insight into its catalytic mechanism and mode of substrate recognition. Initial crystals of DSD diffracted to 2.7 Ä resolution, but exhibited strong twinning. A redesigned construct has recently yielded crystals that diffract to similar resolution, but with a significantly reduced tendency toward twinning. Interestingly, sequence analysis of P. putida DSD reveals that the protein is in fact a fusion of two distinct domains: an N-terminal sugar phosphate isomerase-like domain associated with DSD activity, and a C-terminal hydroxyphenylpyruvate dioxygenase (HPPD)-like domain with unknown functional significance. Structural characterization of the protein may provide novel insight into the functional relevance of the unusual HPPD-like domain.

scholarly journals An unprecedented dioxygen species revealed by serial femtosecond rotation crystallography in copper nitrite reductase

IUCrJ ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Thomas P. Halsted ◽  
Keitaro Yamashita ◽  
Kunio Hirata ◽  
Hideo Ago ◽  
Go Ueno ◽  
...  
Keyword(s):  
Nitrite Reductase ◽  
Active Sites ◽  
Pulse Length ◽  
Binding Mode ◽  
X Ray ◽  
Clear Cut ◽  
Radiation Induced ◽  
Induced Changes ◽  
Diatomic Ligand ◽  
Insight Into

Synchrotron-based X-ray structural studies of ligand-bound enzymes are powerful tools to further our understanding of reaction mechanisms. For redox enzymes, it is necessary to study both the oxidized and reduced active sites to fully elucidate the reaction, an objective that is complicated by potential X-ray photoreduction. In the presence of the substrate, this can be exploited to construct a structural movie of the events associated with catalysis. Using the newly developed approach of serial femtosecond rotation crystallography (SF-ROX), an X-ray damage-free structure of the as-isolated copper nitrite reductase (CuNiR) was visualized. The sub-10 fs X-ray pulse length from the SACLA X-ray free-electron laser allowed diffraction data to be collected to 1.6 Å resolution in a `time-frozen' state. The extremely short duration of the X-ray pulses ensures the capture of data prior to the onset of radiation-induced changes, including radiolysis. Unexpectedly, an O2 ligand was identified bound to the T2Cu in a brand-new binding mode for a diatomic ligand in CuNiRs. The observation of O2 in a time-frozen structure of the as-isolated oxidized enzyme provides long-awaited clear-cut evidence for the mode of O2 binding in CuNiRs. This provides an insight into how CuNiR from Alcaligenes xylosoxidans can function as an oxidase, reducing O2 to H2O2, or as a superoxide dismutase (SOD) since it was shown to have ∼56% of the dismutase activity of the bovine SOD enzyme some two decades ago.

Structural Insight into Redox Dynamics of Copper Bound N-Truncated Amyloid-β Peptides from in Situ X-ray Absorption Spectroscopy

2018 ◽  
Vol 57 (18) ◽  
pp. 11422-11435 ◽  
Author(s):  
Victor A. Streltsov ◽  
Ruwini S. K. Ekanayake ◽  
Simon C. Drew ◽  
Christopher T. Chantler ◽  
Stephen P. Best
Keyword(s):  
Absorption Spectroscopy ◽  
Amyloid Β ◽  
X Ray ◽  
Structural Insight ◽  
X Ray Absorption ◽  
Insight Into ◽  
Redox Dynamics

S K-Edge X-ray Absorption Spectroscopic Investigation of the Ni-Containing Superoxide Dismutase Active Site:  New Structural Insight into the Mechanism

2004 ◽  
Vol 126 (10) ◽  
pp. 3018-3019 ◽  
Author(s):  
Robert K. Szilagyi ◽  
Peter A. Bryngelson ◽  
Michael J. Maroney ◽  
Britt Hedman ◽  
Keith O. Hodgson ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Spectroscopic Investigation ◽  
X Ray ◽  
Structural Insight ◽  
X Ray Absorption ◽  
Insight Into

Structural Insight into the Self-Assembly of a Pharmaceutically Optimized Insulin Analogue Obtained by Small-Angle X-ray Scattering

2020 ◽  
Vol 17 (8) ◽  
pp. 2809-2820
Author(s):  
Lasse Sander Dreyer ◽  
Jesper Nygaard ◽  
Leila Malik ◽  
Thomas Hoeg-Jensen ◽  
Rasmus Høiberg-Nielsen ◽  
...  
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Insulin Analogue ◽  
The Self ◽  
X Ray ◽  
X Ray Scattering ◽  
Structural Insight ◽  
Insight Into ◽  
Ray Scattering

scholarly journals Structural insight into intermediate filament assembly using small-angle X-ray scattering

2006 ◽  
Vol 62 (a1) ◽  
pp. s141-s141
Author(s):  
A. V. Sokolova ◽  
L. Kreplak ◽  
L. P. Kurochkina ◽  
D. I. Svergun ◽  
T. Wedig ◽  
...  
Keyword(s):  
Small Angle ◽  
Intermediate Filament ◽  
X Ray ◽  
Filament Assembly ◽  
X Ray Scattering ◽  
Structural Insight ◽  
Insight Into ◽  
Ray Scattering

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

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