Functional and structural characterization of two Bacillus megaterium nitroreductases biotransforming the herbicide mesotrione

2016 ◽  
Vol 473 (10) ◽  
pp. 1443-1453 ◽  
Author(s):  
Louis Carles ◽  
Pascale Besse-Hoggan ◽  
Muriel Joly ◽  
Armelle Vigouroux ◽  
Solange Moréra ◽  
...  
Keyword(s):  
Bacillus Megaterium ◽  
Structural Characterization ◽  
Agricultural Soil ◽  
Nitro Compounds ◽  
Type I ◽  
Parent Molecule ◽  
Nitrobenzoic Acid ◽  
Ping Pong ◽  
Optimal Ph

Mesotrione is a selective herbicide belonging to the triketone family, commonly used on maize cultures since 2003. A mesotrione-transforming Bacillus megaterium Mes11 strain isolated from an agricultural soil was used as a model to identify the key enzymes initiating the biotransformation of this herbicide. Two enzymes (called NfrA1 and NfrA2/YcnD) were identified, and functionally and structurally characterized. Both belong to the NfsA FRP family of the nitro-FMN reductase superfamily (type I oxygen-insensitive nitroreductase) and show optimal pH and temperature of 6–6.5 and 23–25°C, respectively. Both undergo a Ping Pong Bi Bi mechanism, with NADPH and NADPH/NADH as cofactors for NfrA1 and NfrA2/YcnD, respectively. It is interesting that both can also reduce various nitro compounds including pesticides, antibiotics, one prodrug and 4-methylsulfonyl-2-nitrobenzoic acid, one of the mesotrione metabolites retrieved from the environment. The present study constitutes the first identification of mesotrione-transforming enzymes. These enzymes (or their corresponding genes) could be used as biomarkers to predict the capacity of ecosystems to transform mesotrione and assess their contamination by both the parent molecule and/or the metabolites.

Cloning, Expression and Characterization of a Monooxygenase P450BM3 from Bacillus megaterium ALA2

2012 ◽  
Vol 518-523 ◽  
pp. 5533-5538
Author(s):  
Ting Wang ◽  
Liang Liang Wang ◽  
Xun Li
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Linoleic Acid ◽  
Bacillus Megaterium ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
Nadph Oxidation ◽  
First Time ◽  
Optimal Ph

Cytochrome P450 monooxygenases are enzymes which are capable of oxidising saturated and unsaturated substrates. P450BM3 from Bacillus megaterium is one of this family. For the first time, the cyp gene for coding P450BM3 from B. megaterium ALA2 has been cloned and expressed in Escherichia coli. The recombinant enzyme is 120 kDa, containing 1049 aa. The highest activity of purified enzyme is 14.8 U/mg towards palmitic acid by monitoring the NADPH oxidation. The optimal pH and temperature were 9.0 and 40°C. The enzyme has higher activity towards linoleic acid, and 2-Methyl-7-octadecene can also be catalyzed which is a precursor of displar.

Expression and biochemical characterization of a novel type I pullulanase from Bacillus megaterium

2016 ◽  
Vol 39 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Shaoqing Yang ◽  
Qiaojuan Yan ◽  
Qingdan Bao ◽  
Jingjing Liu ◽  
Zhengqiang Jiang
Keyword(s):  
Bacillus Megaterium ◽  
Biochemical Characterization ◽  
Type I

Structural characterization of hexameric shell proteins from two types of choline-utilization bacterial microcompartments

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Jessica M. Ochoa ◽  
Oscar Mijares ◽  
Andrea A. Acosta ◽  
Xavier Escoto ◽  
Nancy Leon-Rivera ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Building Blocks ◽  
Type I ◽  
Type Ii ◽  
Protein Subunits ◽  
Bacterial Microcompartments ◽  
Bacterial Microcompartment ◽  
Glycyl Radical ◽  
Shell Proteins

Bacterial microcompartments are large supramolecular structures comprising an outer proteinaceous shell that encapsulates various enzymes in order to optimize metabolic processes. The outer shells of bacterial microcompartments are made of several thousand protein subunits, generally forming hexameric building blocks based on the canonical bacterial microcompartment (BMC) domain. Among the diverse metabolic types of bacterial microcompartments, the structures of those that use glycyl radical enzymes to metabolize choline have not been adequately characterized. Here, six structures of hexameric shell proteins from type I and type II choline-utilization microcompartments are reported. Sequence and structure analysis reveals electrostatic surface properties that are shared between the four types of shell proteins described here.

Fractionation and structural characterization of six purified rhamnogalacturonans type I from flaxseed mucilage

2017 ◽  
Vol 62 ◽  
pp. 273-279 ◽  
Author(s):  
Redouan Elboutachfaiti ◽  
Cédric Delattre ◽  
Anthony Quéro ◽  
Romain Roulard ◽  
Julie Duchêne ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Type I

Synthesis and Structural Characterization of Organically-Modified Microporous Silicates

1998 ◽  
Vol 519 ◽  
Author(s):  
F. Babonneau ◽  
L. Leite ◽  
S. Fonlupt ◽  
F. Ribot ◽  
L. Bergogne ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Nitrogen Adsorption ◽  
Type I ◽  
Silicate Phase ◽  
Organically Modified Silicates ◽  
Bet Method ◽  
Organically Modified ◽  
Acidic Conditions ◽  
Hexagonally Ordered

AbstractOrganically-modified silicates have been synthesized from RSi(OEt)3 (R = CH3, C2H5, C8H17, CH2=CH, C6H5) and TEOS under acidic conditions, in the presence of cethyltrimethylammonium (CTAB). The introduction of RSiO1.5 units with R/Si =0.2, affects the ordering of the expected hexagonal silicate phase, except when R = C6H5. The sample containing phenyl functions was thus submitted to surfactant extraction; calcination at 350°C appears to be more efficient, and less disruptive for the network ordering than a washing procedure in ethanol. Nitrogen adsorption measurements on the hexagonally ordered calcined sample that still contains phenyl groups, yields a type I isotherm, typical of a microporous solid. BET method leads to a surface area of 1000 m2/g and a pore volume of 0.32 cm3/g.

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