scholarly journals The Contribution of Syringopeptin and Syringomycin to Virulence of Pseudomonas syringae pv. syringae strain B301D on the Basis of sypA and syrB1 Biosynthesis Mutant Analysis

2001 ◽  
Vol 14 (3) ◽  
pp. 336-348 ◽  
Author(s):  
Brenda K. Scholz-Schroeder ◽  
Michael L. Hutchison ◽  
Ingeborg Grgurina ◽  
Dennis C. Gross
Keyword(s):  
Pseudomonas Syringae ◽  
High Performance ◽  
Sweet Cherry ◽  
Peptide Structure ◽  
Acid Activation ◽  
Virulence Determinants ◽  
Amino Acid Activation ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Peptide Biosynthesis

Sequencing of an approximately 3.9-kb fragment downstream of the syrD gene of Pseudomonas syringae pv. syringae strain B301D revealed that this region, designated sypA, codes for a peptide synthetase, a multifunctional enzyme involved in the thiotemplate mechanism of peptide biosynthesis. The translated protein sequence encompasses a complete amino acid activation module containing the conserved domains characteristic of peptide synthetases. Analysis of the substrate specificity region of this module indicates that it incorporates 2,3-dehydroaminobutyric acid into the syringopeptin peptide structure. Bioassay and high performance liquid chromatography data confirmed that disruption of the sypA gene in strain B301D resulted in the loss of syringopeptin production. The contribution of syringopeptin and syringomycin to the virulence of P. syringae pv. syringae strain B301D was examined in immature sweet cherry with sypA and syrB1 synthetase mutants defective in the production of the two toxins, respectively. Syringopeptin (sypA) and syringomycin (syrB1) mutants were reduced in virulence 59 and 26%, respectively, compared with the parental strain in cherry, whereas the syringopeptin-syringomycin double mutant was reduced 76% in virulence. These data demonstrate that syringopeptin and syringomycin are major virulence determinants of P. syringae pv. syringae.

scholarly journals Streptogramin B biosynthesis in Streptomyces pristinaespiralis and Streptomyces virginiae: molecular characterization of the last structural peptide synthetase gene.

1997 ◽  
Vol 41 (9) ◽  
pp. 1904-1909 ◽  
Author(s):  
V de Crécy-Lagard ◽  
W Saurin ◽  
D Thibaut ◽  
P Gil ◽  
L Naudin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Activation ◽  
Activation Domains ◽  
Amino Acid Activation ◽  
Streptomyces Virginiae ◽  
Streptomyces Pristinaespiralis ◽  
Degenerate Oligonucleotide ◽  
Peptide Synthetase ◽  
Different Origins

Streptomyces pristinaespiralis and S. virginiae both produce closely related hexadepsipeptide antibiotics of the streptogramin B family. Pristinamycins I and virginiamycins S differ only in the fifth incorporated precursor, di(mono)methylated amine and phenylalanine, respectively. By using degenerate oligonucleotide probes derived from internal sequences of the purified S. pristinaespiralis SnbD and SnbE proteins, the genes from two streptogramin B producers, S. pristinaespiralis and S. virginiae, encoding the peptide synthetase involved in the activation and incorporation of the last four precursors (proline, 4-dimethylparaaminophenylalanine [for pristinamycin I(A)] or phenylalanine [for virginiamycin S], pipecolic acid, and phenylglycine) were cloned. Analysis of the sequence revealed that SnbD and SnbE are encoded by a unique snbDE gene. SnbDE (4,849 amino acids [aa]) contains four amino acid activation domains, four condensation domains, an N-methylation domain, and a C-terminal thioesterase domain. Comparison of the sequences of 55 amino acid-activating modules from different origins confirmed that these sequences contain enough information for the performance of legitimate predictions of their substrate specificity. Partial sequencing (1,993 aa) of the SnbDE protein of S. virginiae allowed comparison of the proline and aromatic acid activation domains of the two species and the identification of coupled frameshift mutations.

scholarly journals A Nonribosomal Peptide Synthetase Gene (mgoA) of Pseudomonas syringae pv. syringae Is Involved in Mangotoxin Biosynthesis and Is Required for Full Virulence

2007 ◽  
Vol 20 (5) ◽  
pp. 500-509 ◽  
Author(s):  
Eva Arrebola ◽  
Francisco M. Cazorla ◽  
Diego Romero ◽  
Alejandro Pérez-García ◽  
Antonio de Vicente
Keyword(s):  
Pseudomonas Syringae ◽  
Chromosomal Region ◽  
Open Reading Frames ◽  
Modular Architecture ◽  
Nonribosomal Peptide ◽  
Peptide Synthetases ◽  
Large Gene ◽  
Peptide Synthetase ◽  
Apical Necrosis ◽  
Reading Frames

Pseudomonas syringae pv. syringae, which causes the bacterial apical necrosis of mango, produces the antimetabolite mangotoxin. We report here the cloning, sequencing, and identity analysis of a chromosomal region of 11.1 kb from strain P. syringae pv. syringae UMAF0158, which is involved in mangotoxin biosynthesis. This chromosomal region contains six complete open reading frames (ORFs), including a large gene (ORF5) with a modular architecture characteristic of nonribosomal peptide synthetases (NRPS) named mgoA. A Tn 5 mutant disrupted in mgoA was defective in mangotoxin production, revealing the involvement of the putative NRPS gene in the biosynthesis of mangotoxin. This derivative strain impaired in mangotoxin production also showed a reduction in virulence as measured by necrotic symptoms on tomato leaflets. Mangotoxin production and virulence were restored fully in the NRPS mutant by complementation with plasmid pCG2-6, which contains an 11,103-bp chromosomal region cloned from the wildtype strain P. syringae pv. syringae UMAF0158 that includes the putative NPRS gene (mgoA). The results demonstrate that mgoA has a role in the virulence of P. syringae pv. syringae. The involvement of an NRPS in the production of an antimetabolite toxin from P. syringae inhibiting ornithine acetyltransferase activity is proposed.

scholarly journals The sypA, sypB, and sypC Synthetase Genes Encode Twenty-Two Modules Involved in the Nonribosomal Peptide Synthesis of Syringopeptin by Pseudomonas syringae pv. syringae B301D

2003 ◽  
Vol 16 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Brenda K. Scholz-Schroeder ◽  
Jonathan D. Soule ◽  
Dennis C. Gross
Keyword(s):  
Amino Acids ◽  
Pseudomonas Syringae ◽  
Open Reading Frames ◽  
Acid Activation ◽  
Linear Type ◽  
Nonribosomal Peptide ◽  
Peptide Cyclization ◽  
Peptide Synthetases ◽  
Binding Pockets ◽  
Plant Pathogen Interaction

Syringopeptin is a necrosis-inducing phytotoxin, composed of 22 amino acids attached to a 3-hydroxy fatty acid tail. Syringopeptin, produced by Pseudomonas syringae pv. syringae, functions as a virulence determinant in the plant-pathogen interaction. A 73,800-bp DNA region was sequenced, and analysis identified three large open reading frames, sypA, sypB, and sypC, that are 16.1, 16.3, and 40.6 kb in size. Sequence analysis of the putative SypA, SypB, and SypC sequences determined that they are homologous to peptide synthetases, containing five, five, and twelve amino acid activation modules, respectively. Each module exhibited characteristic domains for condensation, aminoacyl adenylation, and thiolation. Within the aminoacyl adenylation domain is a region responsible for substrate specificity. Phylogenetic analysis of the substrate-binding pockets resulted in clustering of the 22 syringopeptin modules into nine groups. This clustering reflects the substrate amino acids predicted to be recognized by each of the respective modules based on placement of the syringopeptin NRPS (nonribosomal peptide synthetase) system in the linear (type A) group. Finally, SypC contains two C-terminal thioesterase domains predicted to catalyze the release of syringopeptin from the synthetase and peptide cyclization to form the lactone ring. The syringopeptin synthetases, which carry 22 NRPS modules, represent the largest linear NRPS system described for a prokaryote.

scholarly journals A Physical Map of the Syringomycin and Syringopeptin Gene Clusters Localized to an Approximately 145-kb DNA Region of Pseudomonas syringae pv. syringae Strain B301D

2001 ◽  
Vol 14 (12) ◽  
pp. 1426-1435 ◽  
Author(s):  
Brenda K. Scholz-Schroeder ◽  
Jonathan D. Soule ◽  
Shi-En Lu ◽  
Ingeborg Grgurina ◽  
Dennis C. Gross
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Physical Map ◽  
Regulatory Element ◽  
Gene Clusters ◽  
Gene Encoding ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Genes Encoding ◽  
Size Estimates

Genetic and phenotypic mapping of an approximately 145-kb DraI fragment of Pseudomonas syringae pv. syringae strain B301D determined that the syringomycin (syr) and syringopeptin (syp) gene clusters are localized to this fragment. The syr and syp gene clusters encompass approximately 55 kb and approximately 80 kb, respectively. Both phytotoxins are synthesized by a thiotemplate mechanism of biosynthesis, requiring large multienzymatic proteins called peptide synthetases. Genes encoding peptide synthetases were identified within the syr and syp gene clusters, accounting for 90% of the DraI fragment. In addition, genes encoding regulatory and secretion proteins were localized to the DraI fragment. In particular, the salA gene, encoding a regulatory element responsible for syringomycin production and lesion formation in P. syringae pv. syringae strain B728a, was localized to the syr gene cluster. A putative ATP-binding cassette (ABC) transporter homolog was determined to be physically located in the syp gene cluster, but phenotypically affects production of both phytotoxins. Preliminary size estimates of the syr and syp gene clusters indicate that they represent two of the largest nonribosomal peptide synthetase gene clusters. Together, the syr and syp gene clusters encompass approximately 135 kb of DNA and may represent a genomic island in P. syringae pv. syringae that contributes to virulence in plant hosts.

scholarly journals Molecular Cloning of the Actinomycin Synthetase Gene Cluster from Streptomyces chrysomallus and Functional Heterologous Expression of the Gene Encoding Actinomycin Synthetase II

1998 ◽  
Vol 180 (9) ◽  
pp. 2468-2474 ◽  
Author(s):  
Florian Schauwecker ◽  
Frank Pfennig ◽  
Werner Schröder ◽  
Ullrich Keller
Keyword(s):  
Heterologous Expression ◽  
Cosmid Library ◽  
Acid Activation ◽  
Gene Encoding ◽  
Activation Domains ◽  
Peptide Synthetases ◽  
Peptide Synthetase ◽  
Hybridization Mapping ◽  
Synthetic Oligonucleotides

ABSTRACT The actinomycin synthetases ACMS I, II, and III catalyze the assembly of the acyl peptide lactone precursor of actinomycin by a nonribosomal mechanism. We have cloned the genes of ACMS I (acmA) and ACMS II (acmB) by hybridization screening of a cosmid library of Streptomyces chrysomallusDNA with synthetic oligonucleotides derived from peptide sequences of the two enzymes. Their genes were found to be closely linked and are arranged in opposite orientations. Hybridization mapping and partial sequence analyses indicate that the gene of an additional peptide synthetase, most likely the gene of ACMS III (acmC), is located immediately downstream of acmB in the same orientation. The protein sequence of ACMS II, deduced fromacmB, shows that the enzyme contains two amino acid activation domains, which are characteristic of peptide synthetases, and an additional epimerization domain. Heterologous expression ofacmB from the mel promoter of plasmid PIJ702 inStreptomyces lividans yielded a functional 280-kDa peptide synthetase which activates threonine and valine as enzyme-bound thioesters. It also catalyzes the dipeptide formation of threonyl–l-valine, which is epimerized to threonyl–d-valine. Both of these dipeptides are enzyme bound as thioesters. This catalytic activity is identical to the in vitro activity of ACMS II from S. chrysomallus.

scholarly journals Arabidopsis Displays Centromeric DNA Hypomethylation and Cytological Alterations of Heterochromatin Upon Attack by Pseudomonas syringae

2006 ◽  
Vol 19 (6) ◽  
pp. 577-587 ◽  
Author(s):  
Valeria Pavet ◽  
Cristián Quintero ◽  
Nicolás M. Cecchini ◽  
Alberto L. Rosa ◽  
María E. Alvarez
Keyword(s):  
Pseudomonas Syringae ◽  
High Performance ◽  
Cytosine Methylation ◽  
Methylation Status ◽  
Nuclear Genome ◽  
Microbial Pathogens ◽  
Polymorphism Analysis ◽  
Dna Hypomethylation ◽  
Plastic Components ◽  
Cytological Alterations

Plant tissues display major alterations upon the perception of microbial pathogens. Changes of cytoplasmic and apo-plastic components that sense and transduce plant defenses have been extensively characterized. In contrast, less information is available about modifications affecting the plant nuclear genome under these circumstances. Here, we investigated whether the Arabidopsis thaliana DNA methylation status is altered in tissues responding to the attack of Pseudomonas syringae pv. tomato DC3000. We applied amplified fragment length polymorphism analysis to monitor cytosine methylation at anonymous 5′-CCGG-3′ and 5′-GATC-3′ sites in naïve and infected samples. Plant genomic fragments reducing methylation upon infection, including peri/centromeric repeats such as the 180-bp unit, Athila retrotansposon, and a portion of the nuclear insertion of mitochondrial DNA, were isolated and characterized. P. syringae pv. tomato-induced hypomethylation was detected by high-performance liquid chromatography assays and at the molecular level it did not seem to equally affect all 5-methyl cytosine (5-mC) residues. Nuclei from challenged tissues displayed structural chromatin alterations, including loosening of chromocenters, which also were stimulated by avirulent P. syringae pv. tomato, but not by the P. syringae pv. tomato hrpL¯ mutant. Finally, P. syringae pv. tomato-induced hypomethylation was found to occur in the absence of DNA replication, suggesting that it involves an active demethylation mechanism. All these responses occurred at 1 day postinfection, largely preceding massive plant cell death generated by pathogen attack.

scholarly journals The Mechanism of Amino Acid Activation: the Work of Mahlon Hoagland

2009 ◽  
Vol 284 (25) ◽  
pp. e7-e8
Author(s):  
Nicole Kresge ◽  
Robert D. Simoni ◽  
Robert L. Hill
Keyword(s):  
Amino Acid ◽  
Acid Activation ◽  
Amino Acid Activation

Amino-Acid Activation in Tissues of Early Embryos

Nature ◽  
1961 ◽  
Vol 191 (4792) ◽  
pp. 1006-1007 ◽  
Author(s):  
ELIZABETH M. DEUCHAR
Keyword(s):  
Amino Acid ◽  
Acid Activation ◽  
Amino Acid Activation ◽  
Early Embryos
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