scholarly journals Characterization of Protocatechuate 4,5-Dioxygenase from Pseudarthrobacter phenanthrenivorans Sphe3 and In Situ Reaction Monitoring in the NMR Tube

2021 ◽  
Vol 22 (17) ◽  
pp. 9647
Author(s):  
Epameinondas Tsagogiannis ◽  
Elpiniki Vandera ◽  
Alexandra Primikyri ◽  
Stamatia Asimakoula ◽  
Andreas G. Tzakos ◽  
...  
Keyword(s):  
Enzymatic Reaction ◽  
Transcriptional Unit ◽  
Pcr Analysis ◽  
Reaction Products ◽  
Gene Encoding ◽  
Keto Form ◽  
First Time ◽  
Single Subunit

The current study aims at the functional and kinetic characterization of protocatechuate (PCA) 4,5-dioxygenase (PcaA) from Pseudarthrobacter phenanthrenivorans Sphe3. This is the first single subunit Type II dioxygenase characterized in Actinobacteria. RT-PCR analysis demonstrated that pcaA and the adjacent putative genes implicated in the PCA meta-cleavage pathway comprise a single transcriptional unit. The recombinant PcaA is highly specific for PCA and exhibits Michaelis–Menten kinetics with Km and Vmax values of 21 ± 1.6 μM and 44.8 ± 4.0 U × mg−1, respectively, in pH 9.5 and at 20 °C. PcaA also converted gallate from a broad range of substrates tested. The enzymatic reaction products were identified and characterized, for the first time, through in situ biotransformation monitoring inside an NMR tube. The PCA reaction product demonstrated a keto-enol tautomerization, whereas the gallate reaction product was present only in the keto form. Moreover, the transcriptional levels of pcaA and pcaR (gene encoding a LysR-type regulator of the pathway) were also determined, showing an induction when cells were grown on PCA and phenanthrene. Studying key enzymes in biodegradation pathways is significant for bioremediation and for efficient biocatalysts development.

scholarly journals Molecular Characterization of the Gene Encoding a New AmpC β-Lactamase in a Clinical Strain of Acinetobacter Genomic Species 3

2004 ◽  
Vol 48 (4) ◽  
pp. 1374-1378 ◽  
Author(s):  
Alejandro Beceiro ◽  
Lourdes Dominguez ◽  
Anna Ribera ◽  
Jordi Vila ◽  
Francisca Molina ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Molecular Characterization ◽  
Biochemical Properties ◽  
Clinical Strain ◽  
The Novel ◽  
Gene Encoding ◽  
Genomic Species ◽  
First Time

ABSTRACT A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this β-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC β-lactamase are reported

scholarly journals Identification and Functional Characterization of the CVOMT and EOMT Genes Promoters from Ocimum Basilicum L

2021 ◽  
Author(s):  
Fatemeh Khakdan ◽  
Zahra Shirazi ◽  
Mojtaba Ranjbar
Keyword(s):  
Water Deficit ◽  
Transcriptional Control ◽  
Functional Characterization ◽  
Pcr Analysis ◽  
Water Deficit Stress ◽  
Specific Expression ◽  
Stress Dependent ◽  
First Time ◽  
Dependent Mechanism

Abstract Methyl chavicol and methyl eugenol are important phenylpropanoid compounds previously purified from basil. These compounds are significantly enhanced by the water deficit stress-dependent mechanism. Here, for the first time, pObCVOMT and pObEOMT promoters were extracted by the genome walking method. They were then cloned into the upstream of the β-glucuronidase (GUS) reporter gene to identify the pattern of GUS water deficit stress-specific expression. Histochemical GUS assays showed in transgenic tobacco lines bearing the GUS gene driven by pObCVOMT and pObEOMT promoters, GUS was strongly expressed under water deficit stress. qRT-PCR analysis of pObCVOMT and pObEOMT transgenic plants confirmed the histochemical assays, indicating that the GUS expression is also significantly induced and up-regulated by increasing density of water deficit stress. This indicates these promoters are able to drive inducible expression. The cis-acting elements analysis showed that the pObCVOMT and pObEOMT promoters contained dehydration or water deficit-related transcriptional control elements.

Induction and Transcription Studies of the Dextransucrase Gene in Leuconostoc mesenteroides NRRL B-512F

1999 ◽  
Vol 65 (12) ◽  
pp. 5504-5509 ◽  
Author(s):  
M. Quirasco ◽  
A. López-Munguía ◽  
M. Remaud-Simeon ◽  
P. Monsan ◽  
A. Farrés
Keyword(s):  
High Performance ◽  
Leuconostoc Mesenteroides ◽  
Carbon Sources ◽  
Promoter Sequence ◽  
Culture Conditions ◽  
Start Codon ◽  
Reaction Products ◽  
Product Specificity ◽  
First Time

ABSTRACT Dextransucrase production by Leuconostoc mesenteroidesNRRL B-512F in media containing carbon sources other than sucrose is reported for the first time. Dextransucrases were analyzed by gel electrophoresis and by an in situ activity assay. Their polymers and acceptor reaction products were also compared by 13C nuclear magnetic resonance and high-performance liquid chromatography techniques, respectively. From these analyses, it was found that, independently of the carbon source, L. mesenteroides NRRL B-512F produced dextransucrases of the same size and product specificity. The 5′ ends of dextransucrase mRNAs isolated from cells grown under different culture conditions were identical. Based on this evidence, we conclude that dextransucrases obtained from cells grown on the various carbon sources result from the transcription of the same gene. The control of expression occurs at this level. The low dextransucrase yields from cultures in d-glucose ord-fructose and the enhancement of dextransucrase gene transcription in the presence of sucrose suggest that an activating phenomenon may be involved in the expression mechanism. Dextransucrase mRNA has a size of approximately 4.8 kb, indicating that the gene is located in a monocistronic operon. The transcription start point was localized 34 bp upstream from the ATG start codon. The −10 and −35 sequences found, TATAAT and TTTACA, were highly homologous to the only glycosyltransferase promoter sequence reported for lactic acid bacteria.

scholarly journals The identification and characterization of a testis-specific cDNA during spermatogenesis

2006 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Chen ◽  
Jiarui Hu ◽  
Ping Song ◽  
Wuming Gong
Keyword(s):  
Experimental Validation ◽  
Rna Binding ◽  
Pcr Analysis ◽  
Splicing Factors ◽  
Rt Pcr ◽  
Rich Domain ◽  
Pachytene Spermatocytes ◽  
Identification And Characterization

AbstractUsing bioinformatics and experimental validation, we obtained a cDNA (named srsf) which was exclusively expressed in the mouse testes. RT-PCR analysis showed that srsf mRNA was not expressed in the gonad during the sex determination period or during embryogenesis. In developing mouse tests, srsf expression was first detected on post-natal day 10, reached its highest level on day 23, and then reduced to and remained at a moderate level throughout adulthood. In situ hybridization analysis demonstrated that srsf mRNA was expressed in pachytene spermatocytes and round spermatids in the testes. The predicted protein contains one RNA-binding domain (RBD) and a serine-arginine rich domain (RS), which are characterized by some splicing factors of SR family members. These findings indicate that srsf may play a role during spermatogenesis.

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 Field characterization of the PM<sub>2.5</sub> Aerosol Chemical Speciation Monitor: insights into the composition, sources, and processes of fine particles in eastern China

2017 ◽  
Vol 17 (23) ◽  
pp. 14501-14517 ◽  
Author(s):  
Yunjiang Zhang ◽  
Lili Tang ◽  
Philip L. Croteau ◽  
Olivier Favez ◽  
Yele Sun ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Fine Particles ◽  
Eastern China ◽  
Temporal Variations ◽  
Inorganic Aerosols ◽  
Mass Fractions ◽  
Highly Correlated ◽  
First Time

Abstract. A PM2.5-capable aerosol chemical speciation monitor (Q-ACSM) was deployed in urban Nanjing, China, for the first time to measure in situ non-refractory fine particle (NR-PM2.5) composition from 20 October to 19 November 2015, along with parallel measurements of submicron aerosol (PM1) species by a standard Q-ACSM. Our results show that the NR-PM2.5 species (organics, sulfate, nitrate, and ammonium) measured by the PM2.5-Q-ACSM are highly correlated (r2 > 0.9) with those measured by a Sunset Lab OC  /  EC analyzer and a Monitor for AeRosols and GAses (MARGA). The comparisons between the two Q-ACSMs illustrated similar temporal variations in all NR species between PM1 and PM2.5, yet substantial mass fractions of aerosol species were observed in the size range of 1–2.5 µm. On average, NR-PM1−2.5 contributed 53 % of the total NR-PM2.5, with sulfate and secondary organic aerosols (SOAs) being the two largest contributors (26 and 27 %, respectively). Positive matrix factorization of organic aerosol showed similar temporal variations in both primary and secondary OAs between PM1 and PM2.5, although the mass spectra were slightly different due to more thermal decomposition on the capture vaporizer of the PM2.5-Q-ACSM. We observed an enhancement of SOA under high relative humidity conditions, which is associated with simultaneous increases in aerosol pH, gas-phase species (NO2, SO2, and NH3) concentrations and aerosol water content driven by secondary inorganic aerosols. These results likely indicate an enhanced reactive uptake of SOA precursors upon aqueous particles. Therefore, reducing anthropogenic NOx, SO2, and NH3 emissions might not only reduce secondary inorganic aerosols but also the SOA burden during haze episodes in China.

scholarly journals Identification and Characterization of a Rhodopsin Kinase Gene in the Suckers of Octopus vulgaris: Looking around Using Arms?

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 936
Author(s):  
Al-Sayed Al-Soudy ◽  
Valeria Maselli ◽  
Stefania Galdiero ◽  
Michael J. Kuba ◽  
Gianluca Polese ◽  
...  
Keyword(s):  
3D Structure ◽  
Complete Characterization ◽  
Octopus Vulgaris ◽  
Kinase Gene ◽  
Light Sensing ◽  
Rhodopsin Kinase ◽  
First Time ◽  
Identification And Characterization

In their foraging behavior octopuses rely on arm search movements outside the visual field of the eyes. In these movements the environment is explored primarily by the suckers that line the entire length of the octopus arm. In this study, for the first time, we report the complete characterization of a light-sensing molecule, Ov-GRK1, in the suckers, skin and retina of Octopus vulgaris. We sequenced the O. vulgaris GRK1 gene, defining a phylogenetic tree and performing a 3D structure model prediction. Furthermore, we found differences in relative mRNA expression in different sucker types at several arm levels, and localized it through in situ hybridization. Our findings suggest that the suckers in octopus arms are much more multimodal than was previously shown, adding the potential for light sensing to the already known mechanical and chemical sensing abilities.

Molecular beam homoepitaxial growth of MgO(001)

1994 ◽  
Vol 9 (11) ◽  
pp. 2944-2952 ◽  
Author(s):  
S.A. Chambers ◽  
T.T. Tran ◽  
T.A. Hileman
Keyword(s):  
Electron Spectroscopy ◽  
High Speed ◽  
Molecular Beam ◽  
Step Flow ◽  
Homoepitaxial Growth ◽  
Crystallographic Order ◽  
Step Flow Growth ◽  
First Time

We describe homoepitaxial growth and detailed in situ characterization of MgO(001). We have used, for the first time, high-speed Auger electron spectroscopy as a real-time probe of film composition during growth. Excellent short-range and long-range crystallographic order are achieved in films grown to a thickness of several hundred angstroms in the substrate temperature range of 450 °C to 750 °C. Moreover, the films become more laminar as the growth temperature increases, suggesting that MgO grows homoepitaxially by the step-flow growth mechanism at elevated temperature. The surfaces of films grown at 650°and 750 °C are smoother than those obtained by cleaving MgO(001).

Elucidating the structure of a high-spin σ-phenyliron(iii) species in a live FeCl3–PhZnCl reaction system

2018 ◽  
Vol 54 (12) ◽  
pp. 1481-1484 ◽  
Author(s):  
Zhiliang Huang ◽  
Dongchao Zhang ◽  
Jyh-Fu Lee ◽  
Aiwen Lei
Keyword(s):  
Density Functional ◽  
Reaction System ◽  
Paramagnetic Resonance ◽  
Functional Theory ◽  
System P ◽  
First Time ◽  
X Ray Absorption ◽  
Electron Paramagnetic

Characterization of σ-aryliron(iii) species in a live reaction system: an unknown sextet Ph(THF)FeCl2 species was well-characterized in a live FeCl3–PhZnCl reaction system for the first time by Raman, in situ IR, electron paramagnetic resonance (EPR), X-ray absorption spectroscopic (XAS) and density functional theory (DFT) calculations.

Reactivity, characterization of reaction products and immobilization of lead in water and sediments using quercetin pentaphosphate

2016 ◽  
Vol 18 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Veronica A. Okello ◽  
Francis J. Osonga ◽  
Michael T. Knipfing ◽  
Victor Bushlyar ◽  
Omowunmi A. Sadik
Keyword(s):  
Reaction Products

Quantitative removal and in situ detection of lead from water using naturally derived quercetin pentaphosphate.

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