scholarly journals Structure and Function of the Unusual Tungsten Enzymes Acetylene Hydratase and Class II Benzoyl-Coenzyme A Reductase

2016 ◽  
Vol 26 (1-3) ◽  
pp. 119-137 ◽  
Author(s):  
Matthias Boll ◽  
Oliver Einsle ◽  
Ulrich Ermler ◽  
Peter M.H. Kroneck ◽  
G. Matthias Ullmann
Keyword(s):  
Alkali Metals ◽  
Coenzyme A ◽  
Anaerobic Bacteria ◽  
Class Ii ◽  
Structure And Function ◽  
Organic Chemical ◽  
Strictly Anaerobic ◽  
Dimethyl Sulfoxide Reductase ◽  
Coa Reductase ◽  
And Function

In biology, tungsten (W) is exclusively found in microbial enzymes bound to a bis<i>-</i>pyranopterin cofactor (bis-WPT). Previously known W enzymes catalyze redox oxo/hydroxyl transfer reactions by directly coordinating their substrates or products to the metal. They comprise the W-containing formate/formylmethanofuran dehydrogenases belonging to the dimethyl sulfoxide reductase (DMSOR) family and the aldehyde:ferredoxin oxidoreductase (AOR) families, which form a separate enzyme family within the Mo/W enzymes. In the last decade, initial insights into the structure and function of two unprecedented W enzymes were obtained: the acetaldehyde forming acetylene hydratase (ACH) belongs to the DMSOR and the class II benzoyl-coenzyme A (CoA) reductase (BCR) to the AOR family. The latter catalyzes the reductive dearomatization of benzoyl-CoA to a cyclic diene. Both are key enzymes in the degradation of acetylene (ACH) or aromatic compounds (BCR) in strictly anaerobic bacteria. They are unusual in either catalyzing a nonredox reaction (ACH) or a redox reaction without coordinating the substrate or product to the metal (BCR). In organic chemical synthesis, analogous reactions require totally nonphysiological conditions depending on Hg<sup>2+</sup> (acetylene hydration) or alkali metals (benzene ring reduction). The structural insights obtained pave the way for biological or biomimetic approaches to basic reactions in organic chemistry.

scholarly journals Cyclohexa-1,5-Diene-1-Carbonyl-Coenzyme A (CoA) Hydratases of Geobacter metallireducens and Syntrophus aciditrophicus: Evidence for a Common Benzoyl-CoA Degradation Pathway in Facultative and Strict Anaerobes

2006 ◽  
Vol 189 (3) ◽  
pp. 1055-1060 ◽  
Author(s):  
Franziska Peters ◽  
Yoshifumi Shinoda ◽  
Michael J. McInerney ◽  
Matthias Boll
Keyword(s):  
Coenzyme A ◽  
Anaerobic Bacteria ◽  
Degradation Pathway ◽  
Ring Cleavage ◽  
Strictly Anaerobic ◽  
Significant Activity ◽  
Geobacter Metallireducens ◽  
Sulfate Reducing ◽  
Coa Reductase ◽  
Syntrophus Aciditrophicus

ABSTRACT In the denitrifying bacterium Thauera aromatica, the central intermediate of anaerobic aromatic metabolism, benzoyl-coenzyme A (CoA), is dearomatized by the ATP-dependent benzoyl-CoA reductase to cyclohexa-1,5-diene-1-carbonyl-CoA (dienoyl-CoA). The dienoyl-CoA is further metabolized by a series of β-oxidation-like reactions of the so-called benzoyl-CoA degradation pathway resulting in ring cleavage. Recently, evidence was obtained that obligately anaerobic bacteria that use aromatic growth substrates do not contain an ATP-dependent benzoyl-CoA reductase. In these bacteria, the reactions involved in dearomatization and cleavage of the aromatic ring have not been shown, so far. In this work, a characteristic enzymatic step of the benzoyl-CoA pathway in obligate anaerobes was demonstrated and characterized. Dienoyl-CoA hydratase activities were determined in extracts of Geobacter metallireducens (iron reducing), Syntrophus aciditrophicus (fermenting), and Desulfococcus multivorans (sulfate reducing) cells grown with benzoate. The benzoate-induced genes putatively coding for the dienoyl-CoA hydratases in the benzoate degraders G. metallireducens and S. aciditrophicus were heterologously expressed and characterized. Both gene products specifically catalyzed the reversible hydration of dienoyl-CoA to 6-hydroxycyclohexenoyl-CoA (Km , 80 and 35 μM; V max, 350 and 550 μmol min−1 mg−1, respectively). Neither enzyme had significant activity with cyclohex-1-ene-1-carbonyl-CoA or crotonyl-CoA. The results suggest that benzoyl-CoA degradation proceeds via dienoyl-CoA and 6-hydroxycyclohexanoyl-CoA in strictly anaerobic bacteria. The steps involved in dienoyl-CoA metabolism appear identical in all nonphotosynthetic anaerobic bacteria, although totally different benzene ring-dearomatizing enzymes are present in facultative and obligate anaerobes.

scholarly journals Decarboxylating and Nondecarboxylating Glutaryl-Coenzyme A Dehydrogenases in the Aromatic Metabolism of Obligately Anaerobic Bacteria

2009 ◽  
Vol 191 (13) ◽  
pp. 4401-4409 ◽  
Author(s):  
Simon Wischgoll ◽  
Martin Taubert ◽  
Franziska Peters ◽  
Nico Jehmlich ◽  
Martin von Bergen ◽  
...  
Keyword(s):  
Coenzyme A ◽  
Anaerobic Bacteria ◽  
Oxidative Decarboxylation ◽  
Kinetic Properties ◽  
Strictly Anaerobic ◽  
Amino Acid Residues ◽  
Geobacter Metallireducens ◽  
Sulfate Reducing ◽  
Reverse Transcription Pcr ◽  
Gene Coding

ABSTRACT In anaerobic bacteria using aromatic growth substrates, glutaryl-coenzyme A (CoA) dehydrogenases (GDHs) are involved in the catabolism of the central intermediate benzoyl-CoA to three acetyl-CoAs and CO2. In this work, we studied GDHs from the strictly anaerobic, aromatic compound-degrading organisms Geobacter metallireducens (GDHGeo) (Fe[III] reducing) and Desulfococcus multivorans (GDHDes) (sulfate reducing). GDHGeo was purified from cells grown on benzoate and after the heterologous expression of the benzoate-induced bamM gene. The gene coding for GDHDes was identified after screening of a cosmid gene library. Reverse transcription-PCR revealed that its expression was induced by benzoate; the product was heterologously expressed and isolated. Both wild-type and recombinant GDHGeo catalyzed the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA at similar rates. In contrast, recombinant GDHDes catalyzed only the dehydrogenation to glutaconyl-CoA. The latter compound was decarboxylated subsequently to crotonyl-CoA by the addition of membrane extracts from cells grown on benzoate in the presence of 20 mM NaCl. All GDH enzymes were purified as homotetramers of a 43- to 44-kDa subunit and contained 0.6 to 0.7 flavin adenine dinucleotides (FADs)/monomer. The kinetic properties for glutaryl-CoA conversion were as follows: for GDHGeo, the Km was 30 ± 2 μM and the V max was 3.2 ± 0.2 μmol min−1 mg−1, and for GDHDes, the Km was 52 ± 5 μM and the V max was 11 ± 1 μmol min−1 mg−1. GDHDes but not GDHGeo was inhibited by glutaconyl-CoA. Highly conserved amino acid residues that were proposed to be specifically involved in the decarboxylation of the intermediate glutaconyl-CoA were identified in GDHGeo but are missing in GDHDes. The differential use of energy-yielding/energy-demanding enzymatic processes in anaerobic bacteria that degrade aromatic compounds is discussed in view of phylogenetic relationships and constraints of overall energy metabolism.

scholarly journals ISOLATION OF CELLULAR FATTY ACID DISTRIBUTED IN UNKNOWN RHIZOBIAL STRAINS

2015 ◽  
Vol 2 (2) ◽  
pp. 104-107
Author(s):  
S Pria ◽  
O.N. Shanmugapriya
Keyword(s):  
Fatty Acid ◽  
Biochemical Characterization ◽  
Anaerobic Bacteria ◽  
Cellular Fatty Acid ◽  
Structure And Function ◽  
Soil Samples ◽  
Plate Method ◽  
Membrane Structure And Function ◽  
And Function ◽  
Rhizobial Isolates

Fatty acid (UFA) biosynthesis is essential for the maintenance of membrane structure and function in many groups of anaerobic bacteria. In this study isolation of cellular fatty acid distributed in unknown rhizobial strains collected from five different soil samples by pour plate method using YEMA medium. The five soil sample are namely Klt 1, Alg 2,Bdl 3, Rf 4 and Mdk 5.The isolated rhizobial sample was identified based on morphological and biochemical characterization. Then the purified culture was mass multiplied and used for isolation of fatty acid. The fatty acid profile of five different rhizobial isolates were identified by GC and the result of fatty acid was totally seven fatty acids from Rhizobial isolates. Among them the Myrestic acid (C:14) were present all the isolates respectively.

scholarly journals Tungstoenzymes: Occurrence, Catalytic Diversity and Cofactor Synthesis

Inorganics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 44
Author(s):  
Carola S. Seelmann ◽  
Max Willistein ◽  
Johann Heider ◽  
Matthias Boll
Keyword(s):  
Abc Transporter ◽  
Aromatic Compounds ◽  
Metal Binding ◽  
Active Sites ◽  
Structure And Function ◽  
Hydration Reaction ◽  
Dimethyl Sulfoxide Reductase ◽  
Reduction Of Co2 ◽  
And Function ◽  
Electron Transfers

Tungsten is the heaviest element used in biological systems. It occurs in the active sites of several bacterial or archaeal enzymes and is ligated to an organic cofactor (metallopterin or metal binding pterin; MPT) which is referred to as tungsten cofactor (Wco). Wco-containing enzymes are found in the dimethyl sulfoxide reductase (DMSOR) and the aldehyde:ferredoxin oxidoreductase (AOR) families of MPT-containing enzymes. Some depend on Wco, such as aldehyde oxidoreductases (AORs), class II benzoyl-CoA reductases (BCRs) and acetylene hydratases (AHs), whereas others may incorporate either Wco or molybdenum cofactor (Moco), such as formate dehydrogenases, formylmethanofuran dehydrogenases or nitrate reductases. The obligately tungsten-dependent enzymes catalyze rather unusual reactions such as ones with extremely low-potential electron transfers (AOR, BCR) or an unusual hydration reaction (AH). In recent years, insights into the structure and function of many tungstoenzymes have been obtained. Though specific and unspecific ABC transporter uptake systems have been described for tungstate and molybdate, only little is known about further discriminative steps in Moco and Wco biosynthesis. In bacteria producing Moco- and Wco-containing enzymes simultaneously, paralogous isoforms of the metal insertase MoeA may be specifically involved in the molybdenum- and tungsten-insertion into MPT, and in targeting Moco or Wco to their respective apo-enzymes. Wco-containing enzymes are of emerging biotechnological interest for a number of applications such as the biocatalytic reduction of CO2, carboxylic acids and aromatic compounds, or the conversion of acetylene to acetaldehyde.

scholarly journals 3-Sulfinopropionyl-coenzyme A (3SP-CoA) desulfinase fromAdvenella mimigardefordensisDPN7T: crystal structure and function of a desulfinase with an acyl-CoA dehydrogenase fold

2015 ◽  
Vol 71 (6) ◽  
pp. 1360-1372 ◽  
Author(s):  
Marc Schürmann ◽  
Rob Meijers ◽  
Thomas R. Schneider ◽  
Alexander Steinbüchel ◽  
Michele Cianci
Keyword(s):  
Dehydrogenase Activity ◽  
Flavin Adenine Dinucleotide ◽  
Coenzyme A ◽  
Structure And Function ◽  
Complete Loss ◽  
Catabolic Pathway ◽  
Substrate Complex ◽  
Crystal Complex ◽  
Guanidinium Group ◽  
And Function

3-Sulfinopropionyl-coenzyme A (3SP-CoA) desulfinase (AcdDPN7; EC 3.13.1.4) was identified during investigation of the 3,3′-dithiodipropionic acid (DTDP) catabolic pathway in the betaproteobacteriumAdvenella mimigardefordensisstrain DPN7T. DTDP is an organic disulfide and a precursor for the synthesis of polythioesters (PTEs) in bacteria, and is of interest for biotechnological PTE production. AcdDPN7catalyzes sulfur abstraction from 3SP-CoA, a key step during the catabolism of DTDP. Here, the crystal structures of apo AcdDPN7at 1.89 Å resolution and of its complex with the CoA moiety from the substrate analogue succinyl-CoA at 2.30 Å resolution are presented. The apo structure shows that AcdDPN7belongs to the acyl-CoA dehydrogenase superfamily fold and that it is a tetramer, with each subunit containing one flavin adenine dinucleotide (FAD) molecule. The enzyme does not show any dehydrogenase activity. Dehydrogenase activity would require a catalytic base (Glu or Asp residue) at either position 246 or position 366, where a glutamine and a glycine are instead found, respectively, in this desulfinase. The positioning of CoA in the crystal complex enabled the modelling of a substrate complex containing 3SP-CoA. This indicates that Arg84 is a key residue in the desulfination reaction. An Arg84Lys mutant showed a complete loss of enzymatic activity, suggesting that the guanidinium group of the arginine is essential for desulfination. AcdDPN7is the first desulfinase with an acyl-CoA dehydrogenase fold to be reported, which underlines the versatility of this enzyme scaffold.

scholarly journals Requirement for Class II Phosphoinositide 3-Kinase C2  in Maintenance of Glomerular Structure and Function

2010 ◽  
Vol 31 (1) ◽  
pp. 63-80 ◽  
Author(s):  
D. P. Harris ◽  
P. Vogel ◽  
M. Wims ◽  
K. Moberg ◽  
J. Humphries ◽  
...  
Keyword(s):  
Class Ii ◽  
Structure And Function ◽  
Phosphoinositide 3 Kinase ◽  
And Function
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