scholarly journals The ABC Transporter BcatrB Affects the Sensitivity of Botrytis cinerea to the Phytoalexin Resveratrol and the Fungicide Fenpiclonil

2001 ◽  
Vol 14 (4) ◽  
pp. 562-571 ◽  
Author(s):  
H. Schoonbeek ◽  
G. Del Sorbo ◽  
M. A. De Waard
Keyword(s):  
Amino Acid ◽  
Plant Defense ◽  
Botrytis Cinerea ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Fungal Pathogens ◽  
Broad Host Range ◽  
Defense Compounds ◽  
Acid Protein ◽  
Chemical Groups

During pathogenesis, fungal pathogens are exposed to a variety of fungitoxic compounds. This may be particularly relevant to Botrytis cinerea, a plant pathogen that has a broad host range and, consequently, is subjected to exposure to many plant defense compounds. In practice, the pathogen is controlled with fungicides belonging to different chemical groups. ATP-binding cassette (ABC) transporters might provide protection against plant defense compounds and fungicides by ATP-driven efflux mechanisms. To test this hypothesis, we cloned BcatrB, an ABC transporter-encoding gene from B. cinerea. This gene encodes a 1,439 amino acid protein with nucleotide binding fold (NBF) and transmembrane (TM) domains in a [NBF-TM6]2 topology. The amino acid sequence has 31 to 67% identity with ABC transporters from various fungi. The expression of BcatrB is up regulated by treatment of B. cinerea germlings with the grapevine phytoalexin resveratrol and the fungicide fenpiclonil. BcatrB replacement mutants are not affected in saprophytic growth on different media but are more sensitive to resveratrol and fenpiclonil than the parental isolate. Furthermore, virulence of ΔBcatrB mutants on grapevine leaves was slightly reduced. These results indicate that BcatrB is a determinant in sensitivity of B. cinerea to plant defense compounds and fungicides.

scholarly journals Novel ABC Transporter Gene, vga(C), Located on a Multiresistance Plasmid from a Porcine Methicillin-Resistant Staphylococcus aureus ST398 Strain

2009 ◽  
Vol 53 (8) ◽  
pp. 3589-3591 ◽  
Author(s):  
Kristina Kadlec ◽  
Stefan Schwarz
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Abc Transporter ◽  
Resistance Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Selective Pressure ◽  
Sequence Type ◽  
Transporter Gene ◽  
Acid Protein ◽  
Amino Acid Protein

ABSTRACT A novel ABC transporter gene, vga(C), was identified on the 14,365-bp multiresistance plasmid pKKS825 in a porcine methicillin (meticillin)-resistant Staphylococcus aureus isolate of sequence type 398. The vga(C) gene encodes a 523-amino-acid protein which confers resistance not only to streptogramin A antibiotics but also to lincosamides and pleuromutilins. Plasmid pKKS825 also carries the resistance genes aadD, tet(L), and dfrK, which may enable the coselection of vga(C) under selective pressure by kanamycin/neomycin, tetracyclines, and trimethoprim.

scholarly journals Mutational Analysis of the tra Locus of the Broad-Host-Range Streptomyces Plasmid pIJ101

2000 ◽  
Vol 182 (16) ◽  
pp. 4500-4504 ◽  
Author(s):  
Gregg S. Pettis ◽  
Stanley N. Cohen
Keyword(s):  
Amino Acid ◽  
Insertional Mutagenesis ◽  
Mutational Analysis ◽  
Plasmid Transfer ◽  
Broad Host Range ◽  
Binding Motifs ◽  
Amino Acid Region ◽  
Acid Protein ◽  
Functionally Diverse ◽  
Amino Acid Protein

ABSTRACT The tra gene of Streptomyces lividansplasmid pIJ101 encodes a 621-amino-acid protein that can mediate both plasmid transfer and the interbacterial transfer of chromosomal genes (i.e., chromosome-mobilizing ability [Cma]) during mating. Here we report the results of in-frame insertional mutagenesis studies aimed at defining regions of Tra required for these functions. While hexameric linker insertions throughout the tra gene affected plasmid and chromosomal gene transfer, insertions in a 200-amino-acid region of the Tra protein that contains presumed nucleotide-binding motifs and that is widely conserved among a functionally diverse family of bacterial and plasmid proteins (K. J. Begg, S. J. Dewar, and W. D. Donachie, J. Bacteriol. 177:6211–6222, 1995) had especially prominent effects on both functions. Insertions near the N terminus of Tra reduced Cma for either circular or linear host chromosomes to a much greater extent than pIJ101 plasmid transfer. Our results suggest that Cma involves Tra functions incremental to those needed for plasmid DNA transfer.

scholarly journals Bcmfs1, a Novel Major Facilitator Superfamily Transporter from Botrytis cinerea, Provides Tolerance towards the Natural Toxic Compounds Camptothecin and Cercosporin and towards Fungicides

2002 ◽  
Vol 68 (10) ◽  
pp. 4996-5004 ◽  
Author(s):  
Keisuke Hayashi ◽  
Henk-jan Schoonbeek ◽  
Maarten A. De Waard
Keyword(s):  
Botrytis Cinerea ◽  
Abc Transporter ◽  
Pathogenic Fungus ◽  
Major Facilitator Superfamily ◽  
Defense Compounds ◽  
Toxic Compounds ◽  
Major Facilitator Superfamily Transporter ◽  
Dmi Fungicides ◽  
Increased Sensitivity ◽  
Major Facilitator

ABSTRACT Bcmfs1, a novel major facilitator superfamily gene from Botrytis cinerea, was cloned, and replacement and overexpression mutants were constructed to study its function. Replacement mutants showed increased sensitivity to the natural toxic compounds camptothecin and cercosporin, produced by the plant Camptotheca acuminata and the plant pathogenic fungus Cercospora kikuchii, respectively. Overexpression mutants displayed decreased sensitivity to these compounds and to structurally unrelated fungicides, such as sterol demethylation inhibitors (DMIs). A double-replacement mutant of Bcmfs1 and the ATP-binding cassette (ABC) transporter gene BcatrD was more sensitive to DMI fungicides than a single-replacement mutant of BcatrD, known to encode an important ABC transporter of DMIs. The sensitivity of the wild-type strain and mutants to DMI fungicides correlated with Bcmfs1 expression levels and with the initial accumulation of oxpoconazole by germlings of these isolates. The results indicate that Bcmfs1 is a major facilitator superfamily multidrug transporter involved in protection against natural toxins and fungicides and has a substrate specificity that overlaps with the ABC transporter BcatrD. Bcmfs1 may be involved in protection of B. cinerea against plant defense compounds during the pathogenic phase of growth on host plants and against fungitoxic antimicrobial metabolites during its saprophytic phase of growth.

scholarly journals Selecting for altered substrate specificity reveals the evolutionary flexibility of ATP-binding cassette transporters

2019 ◽  
Author(s):  
Sriram Srikant ◽  
Rachelle Gaudet ◽  
Andrew W. Murray
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Structural Similarity ◽  
Substrate Selectivity ◽  
Structural Studies ◽  
Transport Activity ◽  
Atp Binding Cassette Transporters ◽  
Evolutionary Paths

AbstractABC transporters are the largest family of ATP-hydrolyzing transporters, with members in every sequenced genome, which transport substrates across membranes. Structural studies and biochemistry highlight the contrast between the global structural similarity of homologous transporters and the enormous diversity of their substrates. How do ABC transporters evolve to carry such diverse molecules and what variations in their amino acid sequence alter their substrate selectivity? We mutagenized the transmembrane domains of a conserved fungal ABC transporter that exports a mating pheromone and selected for mutants that export a non-cognate pheromone. Mutations that alter export selectivity cover a region that is larger than expected for a localized substrate-binding site. Individual selected clones have multiple mutations which have broadly additive contributions to specific transport activity. Our results suggest that multiple positions influence substrate selectivity, leading to alternative evolutionary paths towards selectivity for particular substrates, and explaining the number and diversity of ABC transporters.

scholarly journals Phylogenetic analyses, protein modeling and active site prediction of two pathogenesis related (PR2 and PR3) genes from bread wheat

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257392
Author(s):  
Muhammad Numan ◽  
Shazia Anwer Bukhari ◽  
Mahmood-ur- Rehman ◽  
Ghulam Mustafa ◽  
Bushra Sadia
Keyword(s):  
Molecular Docking ◽  
Amino Acid ◽  
Plant Defense ◽  
Fungal Pathogens ◽  
Tertiary Structure ◽  
Wheat Variety ◽  
Wheat Crop ◽  
Amino Acid Residues ◽  
Beta Glucan ◽  
Pathogenesis Related

Wheat is a major staple food and has been extensively grown around the globe. Sessile nature of plants has exposed them to a lot of biotic and abiotic stresses including fungal pathogen attack. Puccinia graminis f.sp. tritici causes stem rust in the wheat crop and leads to 70% decrease in its production. Pathogenesis-related (PR) proteins provide plants with defense against different fungal pathogens as these proteins have antifungal activities. This study was designed to screen Pakistani wheat varieties for PR2 and PR3 proteins and their in silico characterization. PR2 and PR3 genes were screened and isolated by PCR amplification from wheat variety Chenab-70 and Frontana, respectively. The nucleotide sequences of PR2 and PR3 genes were deposited in GenBank with accession numbers MT303867 and MZ766118, respectively. Physicochemical properties, secondary and tertiary structure predictions, and molecular docking of protein sequences of PR2 and PR3 were performed using different bioinformatics tools and software. PR2 and PR3 genes were identified to encode β–1,3–glucanase and chitinase proteins, respectively. Molecular docking of both PR2 and PR3 proteins with beta-glucan and chitin (i.e. their respective ligands) showed crucial amino acid residues involved in molecular interactions. Conclusively, molecular docking analysis of β–1,3–glucanase and chitinase proteins revealed crucial amino acid residues which are involved in ligand binding and important interactions which might have important role in plant defense against fungal pathogens. Moreover, the active residues in the active sties of these proteins can be identified through mutational studies and resulting information might help understanding how these proteins are involved in plant defense mechanisms.

scholarly journals Screening of Streptococcus pneumoniae ABC Transporter Mutants Demonstrates that LivJHMGF, a Branched-Chain Amino Acid ABC Transporter, Is Necessary for Disease Pathogenesis

2009 ◽  
Vol 77 (8) ◽  
pp. 3412-3423 ◽  
Author(s):  
Shilpa Basavanna ◽  
Suneeta Khandavilli ◽  
Jose Yuste ◽  
Jonathan M. Cohen ◽  
Arthur H. F. Hosie ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Bacterial Pathogens ◽  
Tryptophan Fluorescence ◽  
Growth Defect ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Bacterial ABC transporters are an important class of transmembrane transporters that have a wide variety of substrates and are important for the virulence of several bacterial pathogens, including Streptococcus pneumoniae. However, many S. pneumoniae ABC transporters have yet to be investigated for their role in virulence. Using insertional duplication mutagenesis mutants, we investigated the effects on virulence and in vitro growth of disruption of 9 S. pneumoniae ABC transporters. Several were partially attenuated in virulence compared to the wild-type parental strain in mouse models of infection. For one ABC transporter, required for full virulence and termed LivJHMGF due to its similarity to branched-chain amino acid (BCAA) transporters, a deletion mutant (ΔlivHMGF) was constructed to investigate its phenotype in more detail. When tested by competitive infection, the ΔlivHMGF strain had reduced virulence in models of both pneumonia and septicemia but was fully virulent when tested using noncompetitive experiments. The ΔlivHMGF strain had no detectable growth defect in defined or complete laboratory media. Recombinant LivJ, the substrate binding component of the LivJHMGF, was shown by both radioactive binding experiments and tryptophan fluorescence spectroscopy to specifically bind to leucine, isoleucine, and valine, confirming that the LivJHMGF substrates are BCAAs. These data demonstrate a previously unsuspected role for BCAA transport during infection for S. pneumoniae and provide more evidence that functioning ABC transporters are required for the full virulence of bacterial pathogens.

scholarly journals Disarming the Host: Detoxification of Plant Defense Compounds During Fungal Necrotrophy

2021 ◽  
Vol 12 ◽  
Author(s):  
Nathaniel M. Westrick ◽  
Damon L. Smith ◽  
Mehdi Kabbage
Keyword(s):  
Plant Defense ◽  
Host Range ◽  
Fungal Pathogens ◽  
Enzymatic Catalysis ◽  
Live Cells ◽  
Defense Compounds ◽  
Fungal Host ◽  
Successful Infection ◽  
Multiple Pathogens ◽  
Toxin Sequestration

While fungal biotrophs are dependent on successfully suppressing/subverting host defenses during their interaction with live cells, necrotrophs, due to their lifestyle are often confronted with a suite of toxic metabolites. These include an assortment of plant defense compounds (PDCs) which can demonstrate broad antifungal activity. These PDCs can be either constitutively present in plant tissue or induced in response to infection, but are nevertheless an important obstacle which needs to be overcome for successful pathogenesis. Fungal necrotrophs have developed a number of strategies to achieve this goal, from the direct detoxification of these compounds through enzymatic catalysis and modification, to the active transport of various PDCs to achieve toxin sequestration and efflux. Studies have shown across multiple pathogens that the efficient detoxification of host PDCs is both critical for successful infection and often a determinant factor in pathogen host range. Here, we provide a broad and comparative overview of the various mechanisms for PDC detoxification which have been identified in both fungal necrotrophs and fungal pathogens which depend on detoxification during a necrotrophic phase of infection. Furthermore, the effect that these mechanisms have on fungal host range, metabolism, and disease control will be discussed.

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