scholarly journals Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1841-1849 ◽  
Author(s):  
Monika Coton ◽  
María Fernández ◽  
Hein Trip ◽  
Victor Ladero ◽  
Niels L. Mulder ◽  
...  
Keyword(s):  
Trna Synthetase ◽  
Cloning And Expression ◽  
Clear Correlation ◽  
Tyrosine Decarboxylase ◽  
Gene Encoding ◽  
Polycistronic Mrna ◽  
Tyrosine Concentration ◽  
Putative Phage

A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding tyrosine decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), tyrosine decarboxylase (tdc), tyrosine permease (tyrP) and Na+/H+ antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of tyrosine and tyramine.

scholarly journals Functional Cloning and Expression of the Schizophyllum commune Glucuronoyl Esterase Gene and Characterization of the Recombinant Enzyme

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Dominic W. S. Wong ◽  
Victor J. Chan ◽  
Amanda A. McCormack ◽  
Ján Hirsch ◽  
Peter Biely
Keyword(s):  
Glucuronic Acid ◽  
Active Form ◽  
Schizophyllum Commune ◽  
Constitutive Expression ◽  
Recombinant Enzyme ◽  
Cloning And Expression ◽  
Gene Encoding ◽  
Glucuronoyl Esterase ◽  
Esterase Gene

The gene encoding Schizophyllum commune glucuronoyl esterase was identified in the scaffold 17 of the genome, containing two introns of 50 bp and 48 bp, with a transcript sequence of 1179 bp. The gene was synthesized and cloned into Pichia pastoris expression vector pGAPZα to achieve constitutive expression and secretion of the recombinant enzyme in soluble active form. The purified protein was 53 kD with glycosylation and had an acidic pI of 3.7. Activity analysis on several uronic acids and their derivatives suggests that the enzyme recognized only esters of 4-O-methyl-D-glucuronic acid derivatives, even with a 4-nitrophenyl aglycon but did not hydrolyze the ester of D-galacturonic acid. The kinetic values were Km 0.25 mM, Vmax 16.3 μM⋅min−1, and kcat 9.27 s−1 with 4-nitrophenyl 2-O-(methyl 4-O-methyl-α-D-glucopyranosyluronate)-β-D-xylopyranoside as the substrate.

Cloning and expression in vitro of a gene encoding tRNAArgACG from the nematode Caenorhabditis elegans

Gene ◽  
1991 ◽  
Vol 97 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Dominique Schaller ◽  
Claudia Wittmann ◽  
Rob Linning ◽  
Albert Spicher ◽  
Fritz Müller ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cloning And Expression ◽  
Nematode Caenorhabditis Elegans ◽  
Gene Encoding

scholarly journals Characterization of the Exoglucanase-Encoding Gene PaEXG2 and Study of Its Role in the Biocontrol Activity of Pichia anomala Strain K

2003 ◽  
Vol 93 (9) ◽  
pp. 1145-1152 ◽  
Author(s):  
Cathy Grevesse ◽  
Philippe Lepoivre ◽  
Mohamed Haïssam Jijakli
Keyword(s):  
Marker Gene ◽  
Glycosylation Site ◽  
Pichia Anomala ◽  
Gene Encoding ◽  
Biocontrol Activity ◽  
Monophosphate Decarboxylase ◽  
Uracil Auxotroph

The PaEXG2 gene, encoding an exo-β-1,3-glucanase, was isolated from the biocontrol agent Pichia anomala strain K. PaEXG2 has the capacity for coding an acidic protein of 427 amino acids with a predicted molecular weight of 45.7 kDa, a calculated pI of 4.7, and one potential N-glycosylation site. PaEXG2 was disrupted by the insertion of the URA3 marker gene, encoding orotidine monophosphate decarboxylase in strain KU1, a uracil auxotroph derived from strain K. Strain KU1 showed inferior biocontrol activity and colonization of wounds on apples, compared to the prototrophic strain. Antagonism and colonization were recovered after the restoration of prototrophy by transformation with the URA3 gene. Integrative transformation was shown to be mostly ectopic in strain K descendants (only 4% of integration by homologous recombination). PaEXG2 disruption abolished all detectable extracellular exo-β-1,3-glucanase activity in vitro and in situ but did not affect biocontrol of Botrytis cinerea on wounded apples.

scholarly journals Cloning and Expression of the algL Gene, Encoding the Azotobacter chroococcum Alginate Lyase: Purification and Characterization of the Enzyme

1999 ◽  
Vol 181 (5) ◽  
pp. 1409-1414 ◽  
Author(s):  
Ana Peciña ◽  
Alberto Pascual ◽  
Antonio Paneque
Keyword(s):  
Gene Sequence ◽  
Azotobacter Vinelandii ◽  
Alginate Lyase ◽  
Azotobacter Chroococcum ◽  
Open Reading Frame ◽  
Cloning And Expression ◽  
Gene Encoding ◽  
Reading Frame ◽  
Encoding Gene

ABSTRACT The alginate lyase-encoding gene (algL) ofAzotobacter chroococcum was localized to a 3.1-kbEcoRI DNA fragment that revealed an open reading frame of 1,116 bp. This open reading frame encodes a protein of 42.98 kDa, in agreement with the value previously reported by us for this protein. The deduced protein has a potential N-terminal signal peptide that is consistent with its proposed periplasmic location. The analysis of the deduced amino acid sequence indicated that the gene sequence has a high homology (90% identity) to the Azotobacter vinelandii gene sequence, which has very recently been deposited in the GenBank database, and that it has 64% identity to the Pseudomonas aeruginosa gene sequence but that it has rather low homology (15 to 22% identity) to the gene sequences encoding alginate lyase in other bacteria. The A. chroococcum AlgL protein was overproduced in Escherichia coli and purified to electrophoretic homogeneity in a two-step chromatography procedure on hydroxyapatite and phenyl-Sepharose. The kinetic and molecular parameters of the recombinant alginate lyase are similar to those found for the native enzyme.

scholarly journals Release of Nonstop Ribosomes Is Essential

mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Heather A. Feaga ◽  
Patrick H. Viollier ◽  
Kenneth C. Keiler
Keyword(s):  
Messenger Rna ◽  
Caulobacter Crescentus ◽  
Stop Codon ◽  
Selective Advantage ◽  
Gene Encoding ◽  
Content Type ◽  
Bacterial Phyla ◽  
Almost All

ABSTRACTBacterial ribosomes frequently translate to the 3′ end of an mRNA without terminating at a stop codon. Almost all bacteria use the transfer-messenger RNA (tmRNA)-basedtrans-translation pathway to release these “nonstop” ribosomes and maintain protein synthesis capacity.trans-translation is essential in some species, but in others, such asCaulobacter crescentus,trans-translation can be inactivated. To determine whytrans-translation is dispensable inC. crescentus, a Tn-seq screen was used to identify genes that specifically alter growth in cells lackingssrA, the gene encoding tmRNA. One of these genes,CC1214, was essential in ΔssrAcells. Purified CC1214 protein could release nonstop ribosomesin vitro. CC1214 is a homolog of theEscherichia coliArfB protein, and using the CC1214 sequence, ArfB homologs were identified in the majority of bacterial phyla. Most species in whichssrAhas been deleted contain an ArfB homolog, suggesting that release of nonstop ribosomes may be essential in most or all bacteria.IMPORTANCEGenes that are conserved across large phylogenetic distances are expected to confer a selective advantage. The genes required fortrans-translation,ssrAandsmpB, have been found in >99% of sequenced bacterial genomes, suggesting that they are broadly important. However, these genes can be deleted in some species without loss of viability. The identification and characterization ofC. crescentusArfB reveals whytrans-translation is not essential inC. crescentusand suggests that many other bacteria are likely to use ArfB to survive whentrans-translation is compromised.

scholarly journals Identification and Characterization of the Bacillus thuringiensis phaZ Gene, Encoding New Intracellular Poly-3-Hydroxybutyrate Depolymerase

2006 ◽  
Vol 188 (21) ◽  
pp. 7592-7599 ◽  
Author(s):  
Chi-Ling Tseng ◽  
Hui-Ju Chen ◽  
Gwo-Chyuan Shaw
Keyword(s):  
Bacillus Thuringiensis ◽  
Wild Type ◽  
Gene Encoding ◽  
Significant Similarity ◽  
Phb Depolymerase ◽  
New Type ◽  
Identification And Characterization

ABSTRACTA gene that codes for a novel intracellular poly-3-hydroxybutyrate (PHB) depolymerase has now been identified in the genome ofBacillus thuringiensissubsp.israelensisATCC 35646. This gene, previously annotated as a hypothetical 3-oxoadipate enol-lactonase (PcaD) gene and now designatedphaZ, encodes a protein that shows no significant similarity with any known PHB depolymerase. Purified His-tagged PhaZ could efficiently degrade trypsin-activated native PHB granules as well as artificial amorphous PHB granules and release 3-hydroxybutyrate monomer as a hydrolytic product, but it could not hydrolyze denatured semicrystalline PHB. In contrast, purified His-tagged PcaD ofPseudomonas putidawas unable to degrade trypsin-activated native PHB granules and artificial amorphous PHB granules. TheB. thuringiensisPhaZ was inactive againstp-nitrophenylpalmitate, tributyrin, and triolein. Sonication supernatants of the wild-typeB. thuringiensiscells exhibited a PHB-hydrolyzing activity in vitro, whereas those prepared from aphaZmutant lost this activity. ThephaZmutant showed a higher PHB content than the wild type at late stationary phase of growth in a nutrient-rich medium, indicating that this PhaZ can function as a PHB depolymerase in vivo. PhaZ contains a lipase box-like sequence (G-W-S102-M-G) but lacks a signal peptide. A purified His-tagged S102A variant had lost the PHB-hydrolyzing activity. Taken together, these results indicate thatB. thuringiensisharbors a new type of intracellular PHB depolymerase.

Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE): Biochemical Features and Therapeutic Approaches

2007 ◽  
Vol 27 (1-3) ◽  
pp. 151-163 ◽  
Author(s):  
M. C. Lara ◽  
M. L. Valentino ◽  
J. Torres-Torronteras ◽  
M. Hirano ◽  
R. Martí
Keyword(s):  
Molecular Genetic ◽  
In Vivo Studies ◽  
Gene Encoding ◽  
Mitochondrial Neurogastrointestinal Encephalomyopathy ◽  
Mtdna Replication ◽  
Biochemical Features

Over the last 15 years, important research has expanded our knowledge of the clinical, molecular genetic, and biochemical features of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). The characterization of mitochondrial involvement in this disorder and the seminal determination of its genetic cause, have opened new possibilities for more detailed and deeper studies on the pathomechanisms in this progressive and fatal disease. It has been established that MNGIE is caused by mutations in the gene encoding thymidine phosphorylase (TP), which lead to absolute or nearly complete loss of its catalytic activity, producing systemic accumulations of its substrates, thymidine (dThd) and deoxyuridine (dUrd). Findings obtained from in vitro and in vivo studies indicate that the biochemical imbalances specifically impair mitochondrial DNA (mtDNA) replication, repair, or both leading to mitochondrial dysfunction. We have proposed that therapy for MNGIE should be aimed at reducing the concentrations of these toxic nucleosides to normal or nearly normal levels. The first treatment, allogeneic stem-cell transplantation (alloSCT) reported in 2006, produced a nearly full biochemical correction of the dThd and dUrd imbalances in blood. Clinical follow-up of this and other patients receiving alloSCT is necessary to determine whether this and other therapies based on a permanent restoration of TP will be effective treatment for MNGIE.

scholarly journals The N Terminus of Rotavirus VP2 Is Necessary for Encapsidation of VP1 and VP3

1998 ◽  
Vol 72 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Carl Q.-Y. Zeng ◽  
Mary K. Estes ◽  
Annie Charpilienne ◽  
Jean Cohen
Keyword(s):  
Inner Core ◽  
Major Capsid Protein ◽  
Core Layer ◽  
Structural Protein ◽  
Gene Encoding ◽  
Double Stranded Rna ◽  
N Terminus ◽  
Far Western Blot

ABSTRACT The innermost core of rotavirus is composed of VP2, which forms a protein layer that surrounds the two minor proteins VP1 and VP3, and the genome of 11 segments of double-stranded RNA. This inner core layer surrounded by VP6, the major capsid protein, constitutes double-layered particles that are transcriptionally active. Each gene encoding a structural protein of double-layered particles has been cloned into baculovirus recombinants and expressed in insect cells. Previously, we showed that coexpression of different combinations of the structural proteins of rotavirus double-layered particles results in the formation of virus-like particles (VLPs), and each VLP containing VP1, the presumed RNA-dependent RNA polymerase, possesses replicase activity as assayed in an in vitro template-dependent assay system (C. Q.-Y. Zeng, M. J. Wentz, J. Cohen, M. E. Estes, and R. F. Ramig, J. Virol. 70:2736–2742, 1996). This work reports construction and characterization of VLPs containing a truncated VP2 (VPΔ2, containing amino acids [aa] Met-93 to 880). Expression of VPΔ2 alone resulted in the formation of single-layered Δ2-VLPs. Coexpression of VPΔ2 with VP6 produced double-layered Δ2/6-VLPs. VLPs formed by coexpression of VPΔ2 and VP1 or VP3, or both VP1 and VP3, resulted in the formation of VLPs lacking both VP1 and VP3. The presence of VP6 with VPΔ2 did not result in encapsidation of VP1 and VP3. To determine the domain of VP2 required for binding VP1, far-Western blot analyses using a series of truncated VP2 constructs were performed to test their ability to bind VP1. These analyses showed that (i) full-length VP2 (aa 1 to 880) binds to VP1, (ii) any N-terminal truncation lacking aa 1 to 25 fails to bind VP1, and (iii) a C-terminal 296-aa truncated VP2 construct (aa 1 to 583) maintains the ability to bind VP1. These analyses indicate that the N terminus of rotavirus VP2 is necessary for the encapsidation of VP1 and VP3.

Isolation and characterization of temperature-sensitive mutations in RPA190, the gene encoding the largest subunit of RNA polymerase I from Saccharomyces cerevisiae

1988 ◽  
Vol 8 (10) ◽  
pp. 3997-4008
Author(s):  
M Wittekind ◽  
J Dodd ◽  
L Vu ◽  
J M Kolb ◽  
J M Buhler ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase I ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Mutant Strains ◽  
Polymerase I

The isolation and characterization of temperature-sensitive mutations in RNA polymerase I from Saccharomyces cerevisiae are described. A plasmid carrying RPA190, the gene encoding the largest subunit of the enzyme, was subjected to in vitro mutagenesis with hydroxylamine. Using a plasmid shuffle screening system, five different plasmids were isolated which conferred a temperature-sensitive phenotype in haploid yeast strains carrying the disrupted chromosomal RPA190 gene. These temperature-sensitive alleles were transferred to the chromosomal RPA190 locus for mapping and physiology experiments. Accumulation of RNA was found to be defective in all mutant strains at the nonpermissive temperature. In addition, analysis of pulse-labeled RNA from two mutant strains at 37 degrees C showed that the transcription of rRNA genes was decreased, while that of 5S RNA was relatively unaffected. RNA polymerase I was partially purified from several of the mutant strains grown at the nonpermissive temperature and was shown to be deficient when assayed in vitro. Fine-structure mapping and sequencing of the mutant alleles demonstrated that all five mutations were unique. The rpa190-1 and rpa190-5 mutations are tightly clustered in region I (S.S. Broyles and B. Moss, Proc. Natl. Acad. Sci. USA 83:3141-3145, 1986), the putative zinc-binding region that is common to all eucaryotic RNA polymerase large subunits. The rpa190-3 mutation is located between regions III and IV, and a strain carrying it behaves as a mutant that is defective in the synthesis of the enzyme. This mutation lies within a previously unidentified segment of highly conserved amino acid sequence homology that is shared among the largest subunits of eucaryotic nuclear RNA polymerases. Another temperature-sensitive mutation, rpa190-2, creates a UGA nonsense codon.

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