scholarly journals Pathway of Glycine Betaine Biosynthesis in Aspergillus fumigatus

2013 ◽  
Vol 12 (6) ◽  
pp. 853-863 ◽  
Author(s):  
Karine Lambou ◽  
Andrea Pennati ◽  
Isabel Valsecchi ◽  
Rui Tada ◽  
Stephen Sherman ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Glycine Betaine ◽  
Biochemical Characterization ◽  
Choline Oxidase ◽  
Betaine Aldehyde Dehydrogenase ◽  
Metabolic Intermediate ◽  
Content Type ◽  
Betaine Aldehyde ◽  
Functional Features

ABSTRACTThe choline oxidase (CHOA) and betaine aldehyde dehydrogenase (BADH) genes identified inAspergillus fumigatusare present as a cluster specific for fungal genomes. Biochemical and molecular analyses of this cluster showed that it has very specific biochemical and functional features that make it unique and different from its plant and bacterial homologs.A. fumigatusChoAp catalyzed the oxidation of choline to glycine betaine with betaine aldehyde as an intermediate and reduced molecular oxygen to hydrogen peroxide using FAD as a cofactor.A. fumigatusBadhp oxidized betaine aldehyde to glycine betaine with reduction of NAD+to NADH. Analysis of theAfchoAΔ::HPHandAfbadAΔ::HPHsingle mutants and theAfchoAΔAfbadAΔ::HPHdouble mutant showed thatAfChoAp is essential for the use of choline as the sole nitrogen, carbon, or carbon and nitrogen source during the germination process.AfChoAp andAfBadAp were localized in the cytosol of germinating conidia and mycelia but were absent from resting conidia. Characterization of the mutant phenotypes showed that glycine betaine inA. fumigatusfunctions exclusively as a metabolic intermediate in the catabolism of choline and not as a stress protectant. This study inA. fumigatusis the first molecular, cellular, and biochemical characterization of the glycine betaine biosynthetic pathway in the fungal kingdom.

Cloning and molecular characterization of the betaine aldehyde dehydrogenase involved in the biosynthesis of glycine betaine in white shrimp ( Litopenaeus vannamei )

2017 ◽  
Vol 276 ◽  
pp. 65-74 ◽  
Author(s):  
María F. Delgado-Gaytán ◽  
Jesús A. Rosas-Rodríguez ◽  
Gloria Yepiz-Plascencia ◽  
Ciria G. Figueroa-Soto ◽  
Elisa M. Valenzuela-Soto
Keyword(s):  
Molecular Characterization ◽  
Aldehyde Dehydrogenase ◽  
Litopenaeus Vannamei ◽  
Glycine Betaine ◽  
White Shrimp ◽  
Betaine Aldehyde Dehydrogenase ◽  
Betaine Aldehyde

scholarly journals Isolation and Characterization of the Betaine Aldehyde Dehydrogenase Gene in

2010 ◽  
Vol 4 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Jun Liu ◽  
Huiming Zeng ◽  
Xue Li ◽  
Lixin Xu ◽  
Yingbo Wang ◽  
...  
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Glycine Betaine ◽  
Betaine Aldehyde Dehydrogenase ◽  
Reading Frame ◽  
Betaine Aldehyde ◽  
Isolation And Characterization ◽  
Dehydrogenase Gene ◽  
Ophiopogon Japonicus ◽  
Rapid Amplification

Betaine aldehyde dehydrogenase (BADH) catalyzes the last step in the synthesis of the glycine betaine from choline. The BADH gene from turfgrass Ophiopogon japonicus has not been reported. In this study, we first isolated the full length cDNA of betaine aldehyde dehydrogenase gene (OjBADH) from O. japonicus using Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) and Rapid Amplification of cDNA Ends (RACE) techniques. The OjBADH gene (GenBank accession number: DQ645888) has 1785 nucleotides with the 5’ untranscribed region (UTR) of 63 nucleotides, 3’ UTR of 219 nucleotides, and an open reading frame of 1503 nucleotides. This gene encodes a polypeptide of 500 amino acids. It shares a high homology with BADH genes of other Chenopodiaceae species. The putative protein includes a conservative region of phosphofructokinase, aldehyde dehydrogenase, and glutamy phosphoric acid reductase. Overexpression of OjBADH in transgenic tobacco plants demonstrated 2-2.5 folds increase of glycine betaine content and 60- 85% increase of survival rate under salt tolerance. These results suggested that the O. japonicus BADH gene may be used to engineer plants for salt stress tolerance.

scholarly journals Biochemical Characterization of the Methylmercaptopropionate:Cob(I)alamin Methyltransferase fromMethanosarcina acetivorans

2019 ◽  
Vol 201 (12) ◽  
Author(s):  
He Fu ◽  
Michelle N. Goettge ◽  
William W. Metcalf
Keyword(s):  
Transfer Reaction ◽  
Biochemical Characterization ◽  
Detailed Knowledge ◽  
Coenzyme M ◽  
Metabolic Intermediate ◽  
Content Type ◽  
High Substrate ◽  
Methyl Transfer ◽  
Substrate Concentrations

ABSTRACTMethanogenesis from methylated substrates is initiated by substrate-specific methyltransferases that generate the central metabolic intermediate methyl-coenzyme M. This reaction involves a methyl-corrinoid protein intermediate and one or two cognate methyltransferases. Based on genetic data, theMethanosarcina acetivoransMtpC (corrinoid protein) and MtpA (methyltransferase) proteins were suggested to catalyze the methylmercaptopropionate (MMPA):coenzyme M (CoM) methyl transfer reaction without a second methyltransferase. To test this, MtpA was purified after overexpression in its native host and characterized biochemically. MtpA catalyzes a robust methyl transfer reaction using free methylcob(III)alamin as the donor and mercaptopropionate (MPA) as the acceptor, withkcatof 0.315 s−1and apparentKmfor MPA of 12 μM. CoM did not serve as a methyl acceptor; thus, a second unidentified methyltransferase is required to catalyze the full MMPA:CoM methyl transfer reaction. The physiologically relevant methylation of cob(I)alamin with MMPA, which is thermodynamically unfavorable, was also demonstrated, but only at high substrate concentrations. Methylation of cob(I)alamin with methanol, dimethylsulfide, dimethylamine, and methyl-CoM was not observed, even at high substrate concentrations. Although the corrinoid protein MtpC was poorly expressed alone, a stable MtpA/MtpC complex was obtained when both proteins were coexpressed. Biochemical characterization of this complex was not feasible, because the corrinoid cofactor of this complex was in the inactive Co(II) state and was not reactivated by incubation with strong reductants. The MtsF protein, composed of both corrinoid and methyltransferase domains, copurifies with the MtpA/MtpC, suggesting that it may be involved in MMPA metabolism.IMPORTANCEMethylmercaptopropionate (MMPA) is an environmentally significant molecule produced by degradation of the abundant marine metabolite dimethylsulfoniopropionate, which plays a significant role in the biogeochemical cycles of both carbon and sulfur, with ramifications for ecosystem productivity and climate homeostasis. Detailed knowledge of the mechanisms for MMPA production and consumption is key to understanding steady-state levels of this compound in the biosphere. Unfortunately, the biochemistry required for MMPA catabolism under anoxic conditions is poorly characterized. The data reported here validate the suggestion that the MtpA protein catalyzes the first step in the methanogenic catabolism of MMPA. However, the enzyme does not catalyze a proposed second step required to produce the key intermediate, methyl coenzyme M. Therefore, the additional enzymes required for methanogenic MMPA catabolism await discovery.

scholarly journals Structure-Based Mutational Studies of Substrate Inhibition of Betaine Aldehyde Dehydrogenase BetB from Staphylococcus aureus

2014 ◽  
Vol 80 (13) ◽  
pp. 3992-4002 ◽  
Author(s):  
Chao Chen ◽  
Jeong Chan Joo ◽  
Greg Brown ◽  
Ekaterina Stolnikova ◽  
Andrei S. Halavaty ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Aldehyde Dehydrogenase ◽  
Active Sites ◽  
Mutational Analysis ◽  
Substrate Binding ◽  
Substrate Inhibition ◽  
Betaine Aldehyde Dehydrogenase ◽  
Uncharacterized Protein ◽  
Content Type ◽  
Betaine Aldehyde

ABSTRACTInhibition of enzyme activity by high concentrations of substrate and/or cofactor is a general phenomenon demonstrated in many enzymes, including aldehyde dehydrogenases. Here we show that the uncharacterized protein BetB (SA2613) fromStaphylococcus aureusis a highly specific betaine aldehyde dehydrogenase, which exhibits substrate inhibition at concentrations of betaine aldehyde as low as 0.15 mM. In contrast, the aldehyde dehydrogenase YdcW fromEscherichia coli, which is also active against betaine aldehyde, shows no inhibition by this substrate. Using the crystal structures of BetB and YdcW, we performed a structure-based mutational analysis of BetB and introduced the YdcW residues into the BetB active site. From a total of 32 mutations, those in five residues located in the substrate binding pocket (Val288, Ser290, His448, Tyr450, and Trp456) greatly reduced the substrate inhibition of BetB, whereas the double mutant protein H448F/Y450L demonstrated a complete loss of substrate inhibition. Substrate inhibition was also reduced by mutations of the semiconserved Gly234 (to Ser, Thr, or Ala) located in the BetB NAD+binding site, suggesting some cooperativity between the cofactor and substrate binding sites. Substrate docking analysis of the BetB and YdcW active sites revealed that the wild-type BetB can bind betaine aldehyde in both productive and nonproductive conformations, whereas only the productive binding mode can be modeled in the active sites of YdcW and the BetB mutant proteins with reduced substrate inhibition. Thus, our results suggest that the molecular mechanism of substrate inhibition of BetB is associated with the nonproductive binding of betaine aldehyde.

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