scholarly journals Cloning and Disruption of pgx4 Encoding an In Planta Expressed Exopolygalacturonase from Fusarium oxysporum

2000 ◽  
Vol 13 (4) ◽  
pp. 359-365 ◽  
Author(s):  
F. I. García-Maceira ◽  
Antonio Di Pietro ◽  
M. Isabel G. Roncero
Keyword(s):  
Amino Acid ◽  
Fusarium Oxysporum ◽  
Vascular Tissue ◽  
Single Copy ◽  
Gene Replacement ◽  
Amino Acid Sequences ◽  
In Planta ◽  
Calculated Molecular Mass ◽  
Tomato Plants

Fusarium oxysporum f. sp. lycopersici, the causal agent of tomato vascular wilt, produces an array of pectinolytic enzymes, including at least two exo-α1,4-polygalac-turonases (exoPGs). A gene encoding an exoPG, pgx4, was isolated with degenerate polymerase chain reaction primers derived from amino acid sequences conserved in two fungal exoPGs. pgx4 encodes a 454 amino acid polypeptide with nine potential N-glycosylation sites and a putative 21 amino acid N-terminal signal peptide. The deduced mature protein has a calculated molecular mass of 47.9 kDa, a pI of 8.0, and 51 and 49% identity with the exoPGs of Cochliobolus carbonum and Aspergillus tubingensis, respectively. The gene is present in a single copy in different formae speciales of F. oxysporum. Expression of pgx4 was detected during in vitro growth on pectin, polygalacturonic acid, and tomato vascular tissue and in roots and stems of tomato plants infected by F. oxysporum f. sp. lycopersici. Two mutants of F. oxy-sporum f. sp. lycopersici with a copy of pgx4 inactivated by gene replacement were as virulent on tomato plants as the wild-type strain.

scholarly journals Expression of cmg1, an Exo-β-1,3-Glucanase Gene from Coniothyrium minitans, Increases during Sclerotial Parasitism

2001 ◽  
Vol 67 (2) ◽  
pp. 865-871 ◽  
Author(s):  
Gábor Giczey ◽  
Zoltán Kerényi ◽  
László Fülöp ◽  
László Hornok
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Single Copy ◽  
Amino Acid Sequences ◽  
Signal Peptidase ◽  
Coniothyrium Minitans ◽  
Calculated Molecular Mass ◽  
Secretion Signal

ABSTRACT During sclerotial infection of Sclerotinia sclerotiorumthe mycoparasite Coniothyrium minitans penetrates through the host cell wall, which contains β-1,3-glucan as its major component. A PCR-based strategy was used to clone a β-1,3-glucanase-encoding gene, designated cmg1, from a cDNA library of the fungus. The nucleotide and deduced amino acid sequences of this gene showed high levels of similarity to the sequences of other fungal exo-β-1,3-glucanase genes. The calculated molecular mass of the deduced protein (without the predicted 24-amino-acid N-terminal secretion signal peptide) was 83,346 Da, and the estimated pI was 4.73. Saccharomyces cerevisiaeINVSc1 expressing the cmg1 gene secreted a ∼100-kDa β-1,3-glucanase enzyme (as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) into the culture medium. N-terminal sequence analysis of the purified recombinant enzyme revealed that the secreted enzyme starts at Ala-32, seven amino acids downstream from the predicted signal peptidase cleavage site. The purified recombinant glucanase inhibited in vitro mycelial growth ofS. sclerotiorum by 35 and 85% at concentrations of 300 and 600 μg ml−1, respectively. A single copy of thecmg1 gene is present in the genome of C. minitans. Northern analyses indicated increases in the transcript levels of cmg1 due to both carbon starvation and the presence of ground sclerotia of S. sclerotiorum; only slight repression was observed in the presence of 2% glucose. Expression of cmg1 increased during parasitic interaction with S. sclerotiorum.

scholarly journals Zinc phosphate protects tomato plants against Pseudomonas syringae pv. tomato

2021 ◽  
Author(s):  
Mara Quaglia ◽  
Marika Bocchini ◽  
Benedetta Orfei ◽  
Roberto D’Amato ◽  
Franco Famiani ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Zinc Phosphate ◽  
Plant Defence ◽  
In Planta ◽  
Tomato Plants ◽  
Pathogenesis Related Protein ◽  
Defence Responses ◽  
Plant Defence Responses

AbstractThe purpose of this study was to determine whether zinc phosphate treatments of tomato plants (Solanum lycopersicum L.) can attenuate bacterial speck disease severity through reduction of Pseudomonas syringae pv. tomato (Pst) growth in planta and induce morphological and biochemical plant defence responses. Tomato plants were treated with 10 ppm (25.90 µM) zinc phosphate and then spray inoculated with strain DAPP-PG 215, race 0 of Pst. Disease symptoms were recorded as chlorosis and/or necrosis per leaf (%) and as numbers of necrotic spots. Soil treatments with zinc phosphate protected susceptible tomato plants against Pst, with reductions in both disease severity and pathogen growth in planta. The reduction of Pst growth in planta combined with significantly higher zinc levels in zinc-phosphate-treated plants indicated direct antimicrobial toxicity of this microelement, as also confirmed by in vitro assays. Morphological (i.e. callose apposition) and biochemical (i.e., expression of salicylic-acid-dependent pathogenesis-related protein PR1b1 gene) defence responses were induced by the zinc phosphate treatment, as demonstrated by histochemical and qPCR analyses, respectively. In conclusion, soil treatments with zinc phosphate can protect tomato plants against Pst attacks through direct antimicrobial activity and induction of morphological and biochemical plant defence responses.

scholarly journals Charge influences substrate recognition and self-assembly of hydrophobic FG sequences

2016 ◽  
Author(s):  
Wesley G. Chen ◽  
Jacob Witten ◽  
Scott C. Grindy ◽  
Niels Holten-Andersen ◽  
Katharina Ribbeck
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Amino Acid Sequences ◽  
Nuclear Pore ◽  
Selective Binding ◽  
Charged Amino Acids ◽  
Essential Components ◽  
Transport Receptors

AbstractThe nuclear pore complex controls the passage of molecules via hydrophobic phenylalanine-glycine (FG) domains on nucleoporins. Such FG-domains consist of repeating units of FxFG, FG, or GLFG sequences, which can be interspersed with highly charged amino acid sequences. Despite the high density of charge exhibited in certain FG-domains, if and how charge influences FG-domain self-assembly and selective binding of nuclear transport receptors is largely unexplored. Studying how individual charged amino acids contribute to nuclear pore selectivity is challenging with modern in vivo and in vitro techniques due to the complexity of nucleoporin sequences. Here, we present a rationally designed approach to deconstruct essential components of nucleoporins down to 14 amino acid sequences. With these nucleoporin-based peptides, we systematically dissect how charge type and placement of charge influences self-assembly and selective binding of FG-containing gels. Specifically, we find that charge type determines which hydrophobic substrates FG sequences recognize while spatial localization of charge tunes hydrophobic self-assembly and receptor selectivity of FG sequences.

scholarly journals In vitro and In Silico Approach For Characterization of Antimicrobial Peptide From Probiotics Against Staphylococcus Aureus and Escherichia Coli

2021 ◽  
Author(s):  
Amrutha Bindu ◽  
Lakshmi Devi
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Lactobacillus Plantarum ◽  
Exchange Chromatography ◽  
Amino Acid Sequences ◽  
Proteinase K ◽  
Kinetic Assay ◽  
Wide Range

Abstract The focus of present study was to characterize antimicrobial peptide produced by probiotic cultures, Enterococcus durans DB-1aa (MCC4243), Lactobacillus plantarum Cu2-PM7 (MCC4246) and Lactobacillus fermentum Cu3-PM8 (MCC4233) against Staphylococus aureus and E. coli. The growth kinetic assay revealed 24 h of incubation to be optimum for bacteriocin production. The partially purified compound after ion-exchange chromatography was found to be thermoresistant and stable under wide range of pH. The compound was sensitive to proteinase-K, but resistant to trypsin, a-amylase and lipase. The apparent molecular weight of bacteriocin from MCC4243 and MCC4246 was found to be 3.5 KDa. Translated partial amino acid sequence of plnA gene in MCC4246 displayed 48 amino acid sequences showing 100% similarity with plantaricin A of Lactobacillus plantarum (WP_0036419). The sequence revealed 7 β sheets, 6 α sheets, 6 predicted coils and 9 predicted turns. The functions on cytoplasm show 10.82 isoelectric point and 48.6% hydrophobicity. The molecular approach of using Geneious Prime software and protein prediction data base for characterization of bacteriocin is novel and predicts “KSSAYSLQMGATAIKQVKKLFKKWGW” as peptide responsible for antimicrobial activity. The study provides information about broad spectrum bacteriocin in native probiotic culture and paves a way towards its application in functional foods as biopreservative agents.

Differentiating closely affiliated Dehalococcoides lineages by a novel genetic marker identified via computational pangenome analysis

2021 ◽  
Author(s):  
Siyan Zhao ◽  
Chen Zhang ◽  
Matthew J. Rogers ◽  
Xuejie Zhao ◽  
Jianzhong He
Keyword(s):  
Amino Acid ◽  
Microbial Communities ◽  
Genetic Marker ◽  
Genetic Markers ◽  
Unknown Function ◽  
Computational Approach ◽  
Amino Acid Sequences ◽  
Reductive Dehalogenation ◽  
Wide Range

As a group, Dehalococcoides dehalogenate a wide range of organohalide pollutants but the range of organohalide compounds that can be utilized for reductive dehalogenation differs among the Dehalococcoides strains. Dehalococcoides lineages cannot be reliably disambiguated in mixed communities using typical phylogenetic markers, which often confounds bioremediation efforts. Here, we describe a computational approach to identify Dehalococcoides genetic markers with improved discriminatory resolution. Screening core genes from the Dehalococcoides pangenome for degree of similarity and frequency of 100% identity found a candidate genetic marker encoding a bacterial neuraminidase repeat (BNR)-containing protein of unknown function. This gene exhibits the fewest completely identical amino acid sequences and among the lowest average amino acid sequence identity in the core pangenome. Primers targeting BNR could effectively discriminate between 40 available BNR sequences ( in silico ) and 10 different Dehalococcoides isolates ( in vitro ). Amplicon sequencing of BNR fragments generated from 22 subsurface soil samples revealed a total of 109 amplicon sequence variants, suggesting a high diversity of Dehalococcoides distributed in environment. Therefore, the BNR gene can serve as an alternative genetic marker to differentiate strains of Dehalococcoides in complicated microbial communities. Importance The challenge of discriminating between phylogenetically similar but functionally distinct bacterial lineages is particularly relevant to the development of technologies seeking to exploit the metabolic or physiological characteristics of specific members of bacterial genera. A computational approach was developed to expedite screening of potential genetic markers among phylogenetically affiliated bacteria. Using this approach, a gene encoding a bacterial neuraminidase repeat (BNR)-containing protein of unknown function was selected and evaluated as a genetic marker to differentiate strains of Dehalococcoides , an environmentally relevant genus of bacteria whose members can transform and detoxify a range of halogenated organic solvents and persistent organic pollutants, in complex microbial communities to demonstrate the validity of the approach. Moreover, many apparently phylogenetically distinct, currently uncharacterized Dehalococcoides were detected in environmental samples derived from contaminated sites.

Proline-106 EPSPS Mutation Imparting Glyphosate Resistance in Goosegrass (Eleusine indica) Emerges in South America

Weed Science ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Hudson K. Takano ◽  
Rafael R. Mendes ◽  
Leonardo B. Scoz ◽  
Ramiro F. Lopez Ovejero ◽  
Jamil Constantin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Rapid Detection ◽  
Resistance Mechanism ◽  
Fold Increase ◽  
In Planta ◽  
Eleusine Indica ◽  
Target Site Resistance ◽  
Resistance Trait

AbstractGlyphosate-resistant (GR) goosegrass [Eleusine indica(L.) Gaertn.] was recently identified in Brazil, but its resistance mechanism was unknown. This study elucidated the resistance mechanism in this species and developed a molecular marker for rapid detection of this target-site resistance trait. The resistance factor for the resistant biotype was 4.4-fold compared with the glyphosate-susceptible (GS) in greenhouse dose–response experiments. This was accompanied by a similar (4-fold) difference in the levels of in vitro andin plantashikimate accumulation in these biotypes. However, there was no difference in uptake, translocation, or metabolism of glyphosate between the GS and GR biotypes. Moreover, both biotypes showed similar values for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) copy number and transcription. Sequencing of a 330-bp fragment of theEPSPSgene identified a single-nucleotide polymorphism that led to a Pro-106-Ser amino acid substitution in the enzyme from the GR biotype. This mutation imparted a 3.8-fold increase in the amount of glyphosate required to inhibit 50% of EPSPS activity, confirming the role of this amino acid substitution in resistance to glyphosate. A quantitative PCR–based genotyping assay was developed for the rapid detection of resistant plants containing this Pro-106-Ser mutation.

Effects of peptide hormone structure on H+ secretion by Necturus gastric mucosa

1976 ◽  
Vol 231 (2) ◽  
pp. 573-578 ◽  
Author(s):  
JM Berkowitz ◽  
M Praissman ◽  
ME LeFevre
Keyword(s):  
Amino Acid ◽  
Gastric Mucosa ◽  
Peptide Hormone ◽  
Amino Acid Sequences ◽  
Gastrointestinal Hormone ◽  
Gastric Tissue ◽  
The Common ◽  
Subsequent Addition ◽  
Lower Molar

The actions of human synthetic gastrin I(G), the C-terminal tetrapeptide of gastrin (T), and the C-terminal octapeptide of cholecystokinin (OP) on acid secretion and transepithelial potential difference (PD) of the isolated Necturus gastric mucosa were determined. All three peptides induced H+ secretion, but the maximum H+ output was less with OP than with G or T. G and OP produced their maximum H+ output at lower molar concentrations than T. G- and OP-stimulated secretion was long sustained, but T-stimulated secretion rapidly returned to basal levels. T- and G-stimulated secretion was partially inhibited by the addition of OP. Evidence is presented that T rapidly disappears from solutions exposed to gastric mucosa, whereas G does not. Washing sensitized the mucosa to subsequent addition of T. The results suggest that the action of the common C-terminal tetrapeptide of G, T, and OP is modified by the preceding amino acid sequences, and that T, the smallest of the three peptides, is rapidly degraded by gastric tissue in vitro. The implications of the work for the study of gastrointestinal hormone structure-function relationships in isolated tissue preparations are discussed.

scholarly journals Identification of Mimotope Peptides Which Bind to the Mycotoxin Deoxynivalenol-Specific Monoclonal Antibody

1999 ◽  
Vol 65 (8) ◽  
pp. 3279-3286 ◽  
Author(s):  
Qiaoping Yuan ◽  
James J. Pestka ◽  
Brandon M. Hespenheide ◽  
Leslie A. Kuhn ◽  
John E. Linz ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Alkaline Phosphatase ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Synthetic Peptide ◽  
Amino Acid Sequences ◽  
In Vitro Translation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Translation System

ABSTRACT Monoclonal antibody 6F5 (mAb 6F5), which recognizes the mycotoxin deoxynivalenol (DON) (vomitoxin), was used to select for peptides that mimic the mycotoxin by employing a library of filamentous phages that have random 7-mer peptides on their surfaces. Two phage clones selected from the random peptide phage-displayed library coded for the amino acid sequences SWGPFPF and SWGPLPF. These clones were designated DONPEP.2 and DONPEP.12, respectively. The results of a competitive enzyme-linked immunosorbent assay (ELISA) suggested that the two phage displayed peptides bound to mAb 6F5 specifically at the DON binding site. The amino acid sequence of DONPEP.2 plus a structurally flexible linker at the C terminus (SWGPFPFGGGSC) was synthesized and tested to determine its ability to bind to mAb 6F5. This synthetic peptide (designated peptide C430) and DON competed with each other for mAb 6F5 binding. When translationally fused with bacterial alkaline phosphatase, DONPEP.2 bound specifically to mAb 6F5, while the fusion protein retained alkaline phosphatase activity. The potential of using DONPEP.2 as an immunochemical reagent in a DON immunoassay was evaluated with a DON-spiked wheat extract. When peptide C430 was conjugated to bovine serum albumin, it elicited antibody specific to peptide C430 but not to DON in both mice and rabbits. In an in vitro translation system containing rabbit reticulocyte lysate, synthetic peptide C430 did not inhibit protein synthesis but did show antagonism toward DON-induced protein synthesis inhibition. These data suggest that the peptides selected in this study bind to mAb 6F5 and that peptide C430 binds to ribosomes at the same sites as DON.

scholarly journals Genetic Analysis of Azole Resistance in the Darlington Strain of Candida albicans

2000 ◽  
Vol 44 (11) ◽  
pp. 2985-2990 ◽  
Author(s):  
Hiroshi Kakeya ◽  
Yoshitsugu Miyazaki ◽  
Haruko Miyazaki ◽  
Katherine Nyswaner ◽  
Brian Grimberg ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Candida Albicans ◽  
Amino Acid ◽  
Genetic Analysis ◽  
Expression System ◽  
Single Copy ◽  
Gene Replacement ◽  
Azole Resistance ◽  
High Level

ABSTRACT High-level azole resistance in the Darlington strain ofCandida albicans was investigated by gene replacement inC. albicans and expression in Saccharomyces cerevisiae. We sequenced the ERG11 gene, which encodes the sterol C14α-demethylase, from our copy of the Darlington strain. Both alleles contained the histidine for tyrosine substitution at position 132 (Y132H) reported in Darlington by others, but we also found a threonine-for-isoleucine substitution (I471T) not previously reported in the C. albicans ERG11. The encoded I471T change in amino acids conferred azole resistance when overexpressed alone and increased azole resistance when added to the Y132H amino acid sequence in an S. cerevisiae expression system. Replacement of one copy of ERG11 in an azole-susceptible strain of C. albicans with a single copy of the Darlington ERG11 resulted in expression of the integrated copy and a modest increase in azole resistance. The profound azole resistance of the Darlington strain is the result of multiple mutations.

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