X-ray Crystal Structures ofMoorella thermoaceticaFprA. Novel Diiron Site Structure and Mechanistic Insights into a Scavenging Nitric Oxide Reductase†,‡

Biochemistry ◽  
2005 ◽  
Vol 44 (17) ◽  
pp. 6492-6501 ◽  
Author(s):  
Radu Silaghi-Dumitrescu ◽  
Donald M. Kurtz, ◽  
Lars G. Ljungdahl ◽  
William N. Lanzilotta
Keyword(s):  
Nitric Oxide ◽  
Crystal Structures ◽  
Nitric Oxide Reductase ◽  
Site Structure ◽  
X Ray ◽  
Diiron Site

X-ray structure of nitric oxide reductase (cytochrome P450nor) at atomic resolution

2001 ◽  
Vol 58 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Hideaki Shimizu ◽  
Sam-Yong Park ◽  
Yoshitsugu Shiro ◽  
Shin-ichi Adachi
Keyword(s):  
Nitric Oxide ◽  
Atomic Resolution ◽  
Nitric Oxide Reductase ◽  
X Ray

Unique Binding of Nitric Oxide to Ferric Nitric Oxide Reductase fromFusarium oxysporumElucidated with Infrared, Resonance Raman, and X-ray Absorption Spectroscopies

1997 ◽  
Vol 119 (33) ◽  
pp. 7807-7816 ◽  
Author(s):  
Eiji Obayashi ◽  
Koki Tsukamoto ◽  
Shin-ichi Adachi ◽  
Satoshi Takahashi ◽  
Masaharu Nomura ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Resonance Raman ◽  
Nitric Oxide Reductase ◽  
X Ray ◽  
X Ray Absorption

Crystallization and Preliminary X-ray Diffraction Studies of Nitric Oxide Reductase Cytochrome P450nor from Fusarium oxysporum

1994 ◽  
Vol 239 (1) ◽  
pp. 158-159 ◽  
Author(s):  
Kazuhiko Nakahara ◽  
Hirofumi Shoun ◽  
Shin-ichi Adachi ◽  
Tetsutaro Iizuka ◽  
Yoshitsugu Shiro
Keyword(s):  
Nitric Oxide ◽  
Fusarium Oxysporum ◽  
Nitric Oxide Reductase ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The active form of quinol-dependent nitric oxide reductase from Neisseria meningitidis is a dimer

IUCrJ ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 404-415
Author(s):  
M. Arif M. Jamali ◽  
Chai C. Gopalasingam ◽  
Rachel M. Johnson ◽  
Takehiko Tosha ◽  
Kazumasa Muramoto ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Proton Transfer ◽  
Neisseria Meningitidis ◽  
Active Site ◽  
Critical Role ◽  
Active Form ◽  
Nitric Oxide Reductase ◽  
Electron Microscopic ◽  
X Ray ◽  
Transfer Channel

Neisseria meningitidis is carried by nearly a billion humans, causing developmental impairment and over 100 000 deaths a year. A quinol-dependent nitric oxide reductase (qNOR) plays a critical role in the survival of the bacterium in the human host. X-ray crystallographic analyses of qNOR, including that from N. meningitidis (NmqNOR) reported here at 3.15 Å resolution, show monomeric assemblies, despite the more active dimeric sample being used for crystallization. Cryo-electron microscopic analysis of the same chromatographic fraction of NmqNOR, however, revealed a dimeric assembly at 3.06 Å resolution. It is shown that zinc (which is used in crystallization) binding near the dimer-stabilizing TMII region contributes to the disruption of the dimer. A similar destabilization is observed in the monomeric (∼85 kDa) cryo-EM structure of a mutant (Glu494Ala) qNOR from the opportunistic pathogen Alcaligenes (Achromobacter) xylosoxidans, which primarily migrates as a monomer. The monomer–dimer transition of qNORs seen in the cryo-EM and crystallographic structures has wider implications for structural studies of multimeric membrane proteins. X-ray crystallographic and cryo-EM structural analyses have been performed on the same chromatographic fraction of NmqNOR to high resolution. This represents one of the first examples in which the two approaches have been used to reveal a monomeric assembly in crystallo and a dimeric assembly in vitrified cryo-EM grids. A number of factors have been identified that may trigger the destabilization of helices that are necessary to preserve the integrity of the dimer. These include zinc binding near the entry of the putative proton-transfer channel and the preservation of the conformational integrity of the active site. The mutation near the active site results in disruption of the active site, causing an additional destabilization of helices (TMIX and TMX) that flank the proton-transfer channel helices, creating an inert monomeric enzyme.

scholarly journals Multistep Photochemical Reactions of Polypyridine-Based Ruthenium Nitrosyl Complexes in Dimethylsulfoxide

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2205
Author(s):  
Nataliia Marchenko ◽  
Pascal G. Lacroix ◽  
Valerii Bukhanko ◽  
Marine Tassé ◽  
Carine Duhayon ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Crystal Structures ◽  
Photochemical Reactions ◽  
X Ray ◽  
Nitrosyl Complexes ◽  
Ruthenium Nitrosyl ◽  
Linkage Isomerization ◽  
The Difference

The photorelease of nitric oxide (NO·) has been investigated in dimethylsulfoxide (DMSO) on two compounds of formula [Ru(R-tpy)(bpy)(NO)](PF6)3, in which bpy stands for 2,2′-bipyridine and R-tpy for the 4′-R-2,2′:6′,2″-terpyridine with R = H and MeOPh. It is observed that both complexes are extremely sensitive to traces of water, leading to an equilibrium between [Ru(NO)] and [Ru(NO2)]. The photoproducts of formula [Ru(R-tpy)(bpy)(DMSO)](PF6)2 are further subjected to a photoreaction leading to a reversible linkage isomerization between the stable Ru-DMSO(S) (sulfur linked) and the metastable Ru-DMSO(O) (oxygen linked) species. A set of 4 [Ru(R-tpy)(bpy)(DMSO)]2+ complexes (R = H, MeOPh, BrPh, NO2Ph) is investigated to characterize the ratio and mechanism of the isomerization which is tentatively related to the difference in absorbance between the Ru-DMSO(S) and Ru-DMSO(O) forms. In addition, the X-ray crystal structures of [Ru(tpy)(bpy)(NO)](PF6)3 and [Ru(MeOPh-tpy)(bpy)(DMSO(S))](PF6)2 are presented.

scholarly journals Characterization of quinol-dependent nitric oxide reductase from Geobacillus stearothermophilus: Enzymatic activity and active site structure

2014 ◽  
Vol 1837 (7) ◽  
pp. 1019-1026 ◽  
Author(s):  
Erina Terasaka ◽  
Norihiro Okada ◽  
Nozomi Sato ◽  
Yoshihiko Sako ◽  
Yoshitsugu Shiro ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Enzymatic Activity ◽  
Active Site ◽  
Geobacillus Stearothermophilus ◽  
Nitric Oxide Reductase ◽  
Site Structure ◽  
Active Site Structure

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

Crystal Structures of Fragments D and Double-D from Fibrinogen and Fibrin

1999 ◽  
Vol 82 (08) ◽  
pp. 271-276 ◽  
Author(s):  
Glen Spraggon ◽  
Stephen Everse ◽  
Russell Doolittle
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Crystal Structures ◽  
Structure And Function ◽  
X Ray ◽  
Long Period ◽  
And Function

IntroductionAfter a long period of anticipation,1 the last two years have witnessed the first high-resolution x-ray structures of fragments from fibrinogen and fibrin.2-7 The results confirmed many aspects of fibrinogen structure and function that had previously been inferred from electron microscopy and biochemistry and revealed some unexpected features. Several matters have remained stubbornly unsettled, however, and much more work remains to be done. Here, we review several of the most significant findings that have accompanied the new x-ray structures and discuss some of the problems of the fibrinogen-fibrin conversion that remain unresolved. * Abbreviations: GPR—Gly-Pro-Arg-derivatives; GPRPam—Gly-Pro-Arg-Pro-amide; GHRPam—Gly-His-Arg-Pro-amide

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