scholarly journals Total Biosynthesis and Diverse Applications of the Nonribosomal Peptide-Polyketide Siderophore Yersiniabactin

2015 ◽  
Vol 81 (16) ◽  
pp. 5290-5298 ◽  
Author(s):  
Mahmoud Kamal Ahmadi ◽  
Samar Fawaz ◽  
Charles H. Jones ◽  
Guojian Zhang ◽  
Blaine A. Pfeifer

ABSTRACTYersiniabactin (Ybt) is a mixed nonribosomal peptide-polyketide natural product natively produced by the pathogenYersinia pestis. The compound enables iron scavenging capabilities upon host infection and is biosynthesized by a nonribosomal peptide synthetase featuring a polyketide synthase module. This pathway has been engineered for expression and biosynthesis usingEscherichia colias a heterologous host. In the current work, the biosynthetic process for Ybt formation was improved through the incorporation of a dedicated step to eliminate the need for exogenous salicylate provision. When this improvement was made, the compound was tested in parallel applications that highlight the metal-chelating nature of the compound. In the first application, Ybt was assessed as a rust remover, demonstrating a capacity of ∼40% compared to a commercial removal agent and ∼20% relative to total removal capacity. The second application tested Ybt in removing copper from a variety of nonbiological and biological solution mixtures. Success across a variety of media indicates potential utility in diverse scenarios that include environmental and biomedical settings.

2017 ◽  
Vol 5 (21) ◽  
Author(s):  
Scarlett Alonso-Carmona ◽  
Blanca Vera-Gargallo ◽  
Rafael R. de la Haba ◽  
Antonio Ventosa ◽  
Horacio Sandoval-Trujillo ◽  
...  

ABSTRACT The draft genome sequence of Saccharomonospora sp. strain LRS4.154, a moderately halophilic actinobacterium, has been determined. The genome has 4,860,108 bp, a G+C content of 71.0%, and 4,525 open reading frames (ORFs). The clusters of PKS and NRPS genes, responsible for the biosynthesis of a large number of biomolecules, were identified in the genome.


Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 257
Author(s):  
Hisayuki Komaki ◽  
Tomohiko Tamura

(1) Background: Phytohabitans is a recently established genus belonging to rare actinomycetes. It has been unclear if its members have the capacity to synthesize diverse secondary metabolites. Polyketide and nonribosomal peptide compounds are major secondary metabolites in actinomycetes and expected as a potential source for novel pharmaceuticals. (2) Methods: Whole genomes of Phytohabitans flavus NBRC 107702T, Phytohabitans rumicis NBRC 108638T, Phytohabitans houttuyneae NBRC 108639T, and Phytohabitans suffuscus NBRC 105367T were sequenced by PacBio. Polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) gene clusters were bioinformatically analyzed in the genome sequences. (3) Results: These four strains harbored 10, 14, 18 and 14 PKS and NRPS gene clusters, respectively. Most of the gene clusters were annotated to synthesis unknown chemistries. (4) Conclusions: Members of the genus Phytohabitans are a possible source for novel and diverse polyketides and nonribosomal peptides.


2018 ◽  
Vol 35 (11) ◽  
pp. 1185-1209 ◽  
Author(s):  
Akimasa Miyanaga ◽  
Fumitaka Kudo ◽  
Tadashi Eguchi

The protein–protein interactions in polyketide synthase–nonribosomal peptide synthetase hybrids are summarized and discussed.


2011 ◽  
Vol 65 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Jigjiddorj Enkh-Amgalan ◽  
Hisayuki Komaki ◽  
Damdinsuren Daram ◽  
Katsuhiko Ando ◽  
Baljinova Tsetseg

2017 ◽  
Vol 199 (21) ◽  
Author(s):  
Lauren M. Petersen ◽  
Kaitlyn LaCourse ◽  
Tim A. Schöner ◽  
Helge Bode ◽  
Louis S. Tisa

ABSTRACT Hemolysins are important virulence factors for many bacterial pathogens, including Serratia marcescens. The role of the major hemolysin gene in the insect pathogen Serratia sp. strain SCBI was investigated using both forward and reverse-genetics approaches. Introduction of the major hemolysin gene into Escherichia coli resulted in a gain of both virulence and hemolytic activity. Inactivation of this hemolysin in Serratia sp. SCBI resulted in a loss of hemolysis but did not attenuate insecticidal activity. Unexpectedly, inactivation of the hemolysin gene in Serratia sp. SCBI resulted in significantly increased motility and increased antimicrobial activity. Reverse transcription-quantitative PCR (qRT-PCR) analysis of mutants with a disrupted hemolysin gene showed a dramatic increase in mRNA levels of a nonribosomal peptide synthetase gene, swrA, which produces the surfactant serrawettin W2. Mutation of the swrA gene in Serratia sp. SCBI resulted in highly varied antibiotic activity, motility, virulence, and hemolysis phenotypes that were dependent on the site of disruption within this 17.75-kb gene. When introduced into E. coli, swrA increases rates of motility and confers antimicrobial activity. While it is unclear how inactivation of the major hemolysin gene influences the expression of swrA, these results suggest that swrA plays an important role in motility and antimicrobial activity in Serratia sp. SCBI. IMPORTANCE The opportunistic Gram-negative bacteria of the genus Serratia are widespread in the environment and can cause human illness. A comparative genomics analysis between Serratia marcescens and a new Serratia species from South Africa, termed Serratia sp. strain SCBI, shows that these two organisms are closely related but differ in pathogenesis. S. marcescens kills Caenorhabditis nematodes, while Serratia sp. SCBI is not harmful and forms a beneficial association with them. This distinction presented the opportunity to investigate potential differences in regulation of common virulence mechanisms between these two species. With the emergence of antibiotic-resistant microorganisms, there is a widespread need to understand the regulation of pathogenesis. The significance of this study is the presentation of evidence for cross-pathway regulation of virulence factors and how the elimination of one mechanism may be compensated for by the upregulation of others.


2016 ◽  
Vol 69 (9) ◽  
pp. 712-718 ◽  
Author(s):  
Hisayuki Komaki ◽  
Natsuko Ichikawa ◽  
Tomohiko Tamura ◽  
Akio Oguchi ◽  
Moriyuki Hamada ◽  
...  

2011 ◽  
Vol 77 (17) ◽  
pp. 6117-6124 ◽  
Author(s):  
Martin F. Kreutzer ◽  
Hirokazu Kage ◽  
Peter Gebhardt ◽  
Barbara Wackler ◽  
Hans P. Saluz ◽  
...  

ABSTRACTA genome mining study in the plant pathogenic bacteriumRalstonia solanacearumGMI1000 unveiled a polyketide synthase/nonribosomal peptide synthetase gene cluster putatively involved in siderophore biosynthesis. Insertional mutagenesis confirmed the respective locus to be operational under iron-deficient conditions and spurred the isolation of the associated natural product. Bioinformatic analyses of the gene cluster facilitated the structural characterization of this compound, which was subsequently identified as the antimycoplasma agent micacocidin. The metal-chelating properties of micacocidin were evaluated in competition experiments, and the cellular uptake of gallium-micacocidin complexes was demonstrated inR. solanacearumGMI1000, indicating a possible siderophore role. Comparative genomics revealed a conservation of the micacocidin gene cluster in defined, but globally dispersed phylotypes ofR. solanacearum.


2012 ◽  
Vol 78 (23) ◽  
pp. 8208-8218 ◽  
Author(s):  
Antonia Gallo ◽  
Kenneth S. Bruno ◽  
Michele Solfrizzo ◽  
Giancarlo Perrone ◽  
Giuseppina Mulè ◽  
...  

ABSTRACTOchratoxin A (OTA), a mycotoxin produced byAspergillusandPenicilliumspecies, is composed of a dihydroisocoumarin ring linked to phenylalanine, and its biosynthetic pathway has not yet been completely elucidated. Most of the knowledge regarding the genetic and enzymatic aspects of OTA biosynthesis has been elucidated inPenicilliumspecies. InAspergillusspecies, onlypksgenes involved in the initial steps of the pathway have been partially characterized. In our study, the inactivation of a gene encoding a nonribosomal peptide synthetase (NRPS) in OTA-producingA. carbonariusITEM 5010 has eliminated the ability of this fungus to produce OTA. This is the first report on the involvement of annrpsgene product in OTA biosynthetic pathway in anAspergillusspecies. The absence of OTA and ochratoxin α, the isocoumaric derivative of OTA, and the concomitant increase of ochratoxin β, the dechloro analog of ochratoxin α, were observed in the liquid culture of transformed strain. The data provide the first evidence that the enzymatic step adding phenylalanine to polyketide dihydroisocoumarin precedes the chlorination step to form OTA inA. carbonariusand that ochratoxin α is a product of hydrolysis of OTA, giving an interesting new insight into the biosynthetic pathway of the toxin.


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