scholarly journals A 2‐Tyr‐1‐carboxylate Mononuclear Iron Center Forms the Active Site of a Paracoccus Dimethylformamidase

2020 ◽  
Vol 59 (39) ◽  
pp. 16961-16966
Author(s):  
Chetan Kumar Arya ◽  
Swati Yadav ◽  
Jonathan Fine ◽  
Ana Casanal ◽  
Gaurav Chopra ◽  
...  
Keyword(s):  
Active Site ◽  
Mononuclear Iron ◽  
Iron Center

scholarly journals A 2‐Tyr‐1‐carboxylate Mononuclear Iron Center Forms the Active Site of a Paracoccus Dimethylformamidase

2020 ◽  
Vol 132 (39) ◽  
pp. 17109-17114
Author(s):  
Chetan Kumar Arya ◽  
Swati Yadav ◽  
Jonathan Fine ◽  
Ana Casanal ◽  
Gaurav Chopra ◽  
...  
Keyword(s):  
Active Site ◽  
Mononuclear Iron ◽  
Iron Center

Spectroscopic studies of the coupled binuclear ferric active site in methemerythrins and oxyhemerythrin: the electronic structure of each iron center and the iron-oxo and iron-peroxide bonds

1989 ◽  
Vol 111 (13) ◽  
pp. 4688-4704 ◽  
Author(s):  
Richard C. Reem ◽  
James M. McCormick ◽  
David E. Richardson ◽  
Frank J. Devlin ◽  
Philip J. Stephens ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Active Site ◽  
Spectroscopic Studies ◽  
Iron Center

scholarly journals Coordination and conformational isomers in mononuclear iron complexes with pertinence to the [FeFe] hydrogenase active site

2014 ◽  
Vol 43 (11) ◽  
pp. 4537-4549 ◽  
Author(s):  
Andreas Orthaber ◽  
Michael Karnahl ◽  
Stefanie Tschierlei ◽  
Daniel Streich ◽  
Matthias Stein ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Active Site ◽  
Iron Complexes ◽  
Computational Studies ◽  
Mononuclear Iron ◽  
Conformational Isomers ◽  
Ligand Modification ◽  
Fe Complexes ◽  
Ir Spectroscopic

6 Fe complexes of the type [Fe(X-bdt)(PR2NPh2)(CO)] were prepared and the possibility to tune their electronic properties by ligand modification was demonstrated. IR spectroscopic and computational studies suggest that the compounds exist as a mixture of isomers in solution.

scholarly journals Purification and Characterization of Carbazole 1,9a-Dioxygenase, a Three-Component Dioxygenase System of Pseudomonas resinovorans Strain CA10

2002 ◽  
Vol 68 (12) ◽  
pp. 5882-5890 ◽  
Author(s):  
Jeong-Won Nam ◽  
Hideaki Nojiri ◽  
Haruko Noguchi ◽  
Hiromasa Uchimura ◽  
Takako Yoshida ◽  
...  
Keyword(s):  
Native Form ◽  
Mononuclear Iron ◽  
Pseudomonas Resinovorans ◽  
Apparent Homogeneity ◽  
Strain Bl21 ◽  
Prosthetic Groups ◽  
Strain Ca10 ◽  
Iron Center

ABSTRACT The carbazole 1,9a-dioxygenase (CARDO) system of Pseudomonas resinovorans strain CA10 consists of terminal oxygenase (CarAa), ferredoxin (CarAc), and ferredoxin reductase (CarAd). Each component of CARDO was expressed in Escherichia coli strain BL21(DE3) as a native form (CarAa) or a His-tagged form (CarAc and CarAd) and was purified to apparent homogeneity. CarAa was found to be trimeric and to have one Rieske type [2Fe-2S] cluster and one mononuclear iron center in each monomer. Both His-tagged proteins were found to be monomeric and to contain the prosthetic groups predicted from the deduced amino acid sequence (His-tagged CarAd, one FAD and one [2Fe-2S] cluster per monomer protein; His-tagged CarAc, one Rieske type [2Fe-2S] cluster per monomer protein). Both NADH and NADPH were effective as electron donors for His-tagged CarAd. However, since the k cat/Km for NADH is 22.3-fold higher than that for NADPH in the 2,6-dichlorophenolindophenol reductase assay, NADH was supposed to be the physiological electron donor of CarAd. In the presence of NADH, His-tagged CarAc was reduced by His-tagged CarAd. Similarly, CarAa was reduced by His-tagged CarAc, His-tagged CarAd, and NADH. The three purified proteins could reconstitute the CARDO activity in vitro. In the reconstituted CARDO system, His-tagged CarAc seemed to be indispensable for electron transport, while His-tagged CarAd could be replaced by some unrelated reductases.

Aerobic catabolism of sterols by microorganisms: key enzymes that open the 3-ketosteroid nucleus

2019 ◽  
Vol 366 (14) ◽  
Author(s):  
Joseph Kreit
Keyword(s):  
Active Site ◽  
Published Data ◽  
Aerobic Degradation ◽  
Key Enzymes ◽  
Mononuclear Iron ◽  
Catalytic Unit

ABSTRACT Aerobic degradation of the sterol tetracyclic nucleus by microorganisms comprises the catabolism of A/B-rings, followed by that of C/D-rings. B-ring rupture at the C9,10-position is a key step involving 3-ketosteroid Δ1-dehydrogenase (KstD) and 3-ketosteroid 9α-hydroxylase (KstH). Their activities lead to the aromatization of C4,5-en-containing A-ring causing the rupture of B-ring. C4,5α-hydrogenated 3-ketosteroid could be produced by the growing microorganism containing a 5α-reductase. In this case, the microorganism synthesizes, in addition to KstD and KstH, a 3-ketosteroid Δ4-(5α)-dehydrogenase (Kst4D) in order to produce the A-ring aromatization, and consequently B-ring rupture. KstD and Kst4D are FAD-dependent oxidoreductases. KstH is composed of a reductase and a monooxygenase. This last component is the catalytic unit; it contains a Rieske-[2Fe-2S] center with a non-haem mononuclear iron in the active site. Published data regarding these enzymes are reviewed.

scholarly journals One enzyme, many reactions: structural basis for the various reactions catalyzed by naphthalene 1,2-dioxygenase

IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 648-656 ◽  
Author(s):  
Daniel J. Ferraro ◽  
Adam Okerlund ◽  
Eric Brown ◽  
S. Ramaswamy
Keyword(s):  
Active Site ◽  
Binding Pocket ◽  
Nonheme Iron ◽  
Structural Basis ◽  
Mononuclear Iron

Rieske nonheme iron oxygenases (ROs) are a well studied class of enzymes. Naphthalene 1,2-dioxygenase (NDO) is used as a model to study ROs. Previous work has shown how side-on binding of oxygen to the mononuclear iron provides this enzyme with the ability to catalyze stereospecific and regiospecificcis-dihydroxylation reactions. It has been well documented that ROs catalyze a variety of other reactions, including mono-oxygenation, desaturation, O- and N-dealkylation, sulfoxidationetc. NDO itself catalyzes a variety of these reactions. Structures of NDO in complex with a number of different substrates show that the orientation of the substrate in the active site controls not only the regiospecificity and stereospecificity, but also the type of reaction catalyzed. It is proposed that the mononuclear iron-activated dioxygen attacks the atoms of the substrate that are most proximal to it. The promiscuity of delivering two products (apparently by two different reactions) from the same substrate can be explained by the possible binding of the substrate in slightly different orientations aided by the observed flexibility of residues in the binding pocket.

The Active Site of the Bacterial Nitric Oxide Reductase Is a Dinuclear Iron Center†

Biochemistry ◽  
1998 ◽  
Vol 37 (38) ◽  
pp. 13102-13109 ◽  
Author(s):  
Janneke Hendriks ◽  
Antony Warne ◽  
Ulrich Gohlke ◽  
Tuomas Haltia ◽  
Claudia Ludovici ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Active Site ◽  
Nitric Oxide Reductase ◽  
Dinuclear Iron ◽  
Iron Center

scholarly journals A Simple Complex on the Verge of Breakdown: Isolation of the Elusive Cyanoformate Ion

Science ◽  
2014 ◽  
Vol 344 (6179) ◽  
pp. 75-78 ◽  
Author(s):  
Luke J. Murphy ◽  
Katherine N. Robertson ◽  
Scott G. Harroun ◽  
Christa L. Brosseau ◽  
Ulrike Werner-Zwanziger ◽  
...  
Keyword(s):  
Active Site ◽  
Theoretical Calculations ◽  
Acc Oxidase ◽  
Dielectric Medium ◽  
Solution Stability ◽  
Stability Studies ◽  
Simple Complex ◽  
Low Dielectric ◽  
Dielectric Media ◽  
Iron Center

Why does cyanide not react destructively with the proximal iron center at the active site of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, an enzyme central to the biosynthesis of ethylene in plants? It has long been postulated that the cyanoformate anion, [NCCO2]–, forms and then decomposes to carbon dioxide and cyanide during this process. We have now isolated and crystallographically characterized this elusive anion as its tetraphenylphosphonium salt. Theoretical calculations show that cyanoformate has a very weak C–C bond and that it is thermodynamically stable only in low dielectric media. Solution stability studies have substantiated the latter result. We propose that cyanoformate shuttles the potentially toxic cyanide away from the low dielectric active site of ACC oxidase before breaking down in the higher dielectric medium of the cell.

scholarly journals Can a Mononuclear Iron(III)‐Superoxo Active Site Catalyze the Decarboxylation of Dodecanoic Acid in UndA to Produce Biofuels?

2019 ◽  
Vol 26 (10) ◽  
pp. 2233-2242 ◽  
Author(s):  
Yen‐Ting Lin ◽  
Agnieszka Stańczak ◽  
Yulian Manchev ◽  
Grit D. Straganz ◽  
Sam P. Visser
Keyword(s):  
Active Site ◽  
Dodecanoic Acid ◽  
Mononuclear Iron
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