Identification of a gene cluster encoding meilingmycin biosynthesis among multiple polyketide synthase contigs isolated from Streptomyces nanchangensis NS3226

2003 ◽  
Vol 180 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Yuhui Sun ◽  
Xiufen Zhou ◽  
Guoquan Tu ◽  
Zixin Deng
2020 ◽  
Vol 11 ◽  
Author(s):  
Jin Lü ◽  
Qingshan Long ◽  
Zhilong Zhao ◽  
Lu Chen ◽  
Weijun He ◽  
...  

Bacteria of the genus Saccharopolyspora produce important polyketide antibiotics, including erythromycin A (Sac. erythraea) and spinosad (Sac. spinosa). We herein report the development of an industrial erythromycin-producing strain, Sac. erythraea HOE107, into a host for the heterologous expression of polyketide biosynthetic gene clusters (BGCs) from other Saccharopolyspora species and related actinomycetes. To facilitate the integration of natural product BGCs and auxiliary genes beneficial for the production of natural products, the erythromycin polyketide synthase (ery) genes were replaced with two bacterial attB genomic integration sites associated with bacteriophages ϕC31 and ϕBT1. We also established a highly efficient conjugation protocol for the introduction of large bacterial artificial chromosome (BAC) clones into Sac. erythraea strains. Based on this optimized protocol, an arrayed BAC library was effectively transferred into Sac. erythraea. The large spinosad gene cluster from Sac. spinosa and the actinorhodin gene cluster from Streptomyces coelicolor were successfully expressed in the ery deletion mutant. Deletion of the endogenous giant polyketide synthase genes pkeA1-pkeA4, the product of which is not known, and the flaviolin gene cluster (rpp) from the bacterium increased the heterologous production of spinosad and actinorhodin. Furthermore, integration of pJTU6728 carrying additional beneficial genes dramatically improved the yield of actinorhodin in the engineered Sac. erythraea strains. Our study demonstrated that the engineered Sac. erythraea strains SLQ185, LJ161, and LJ162 are good hosts for the expression of heterologous antibiotics and should aid in expression-based genome-mining approaches for the discovery of new and cryptic antibiotics from Streptomyces and rare actinomycetes.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 87 ◽  
Author(s):  
Juan F. Martín ◽  
Angelina Ramos ◽  
Paloma Liras

Geldanamycin and the closely related herbimycins A, B, and C are benzoquinone-type ansamycins with antitumoral activity. They are produced by Streptomyces hygroscopicus var. geldanus, Streptomyces lydicus and Streptomyces autolyticus among other Streptomyces strains. Geldanamycins interact with the Hsp-90 chaperone, a protein that has a key role in tumorigenesis of human cells. Geldanamycin is a polyketide antibiotic and the polyketide synthase contain seven modules organized in three geldanamycin synthases genes named gdmAI, gdmAII, and gdmAIII. The loading domain of GdmI activates AHBA, and also related hydroxybenzoic acid derivatives, forming geldanamycin analogues. Three regulatory genes, gdmRI, gdmRII, and gdmRIII were found associated with the geldanamycin gene cluster in S. hygroscopicus strains. GdmRI and GdmRII are LAL-type (large ATP binding regulators of the LuxR family) transcriptional regulators, while GdmRIII belongs to the TetR-family. All three are positive regulators of geldanamycin biosynthesis and are strictly required for expression of the geldanamycin polyketide synthases. In S. autolyticus the gdmRIII regulates geldanamycin biosynthesis and also expression of genes in the elaiophylin gene cluster, an unrelated macrodiolide antibiotic. The biosynthesis of geldanamycin is very sensitive to the inorganic phosphate concentration in the medium. This regulation is exerted through the two components system PhoR-PhoP. The phoRP genes of S. hygroscopicus are linked to phoU encoding a transcriptional modulator. The phoP gene was deleted in S. hygroscopicus var geldanus and the mutant was unable to grow in SPG medium unless supplemented with 5 mM phosphate. Also, the S. hygroscopicus pstS gene involved in the high affinity phosphate transport was cloned, and PhoP binding sequences (PHO boxes), were found upstream of phoU, phoRP, and pstS; the phoRP-phoU sequences were confirmed by EMSA and nuclease footprinting protection assays. The PhoP binding sequence consists of 11 nucleotide direct repeat units that are similar to those found in S. coelicolor Streptomyces avermitilis and other Streptomyces species. The available genetic information provides interesting tools for modification of the biosynthetic and regulatory mechanisms in order to increase geldanamycin production and to obtain new geldanamycin analogues with better antitumor properties.


2007 ◽  
Vol 6 (7) ◽  
pp. 1210-1218 ◽  
Author(s):  
Daren W. Brown ◽  
Robert A. E. Butchko ◽  
Mark Busman ◽  
Robert H. Proctor

ABSTRACT Fumonisins are mycotoxins produced by some Fusarium species and can contaminate maize or maize products. Ingestion of fumonisins is associated with diseases, including cancer and neural tube defects, in humans and animals. In fungi, genes involved in the synthesis of mycotoxins and other secondary metabolites are often located adjacent to each other in gene clusters. Such genes can encode structural enzymes, regulatory proteins, and/or proteins that provide self-protection. The fumonisin biosynthetic gene cluster includes 16 genes, none of which appear to play a role in regulation. In this study, we identified a previously undescribed gene (FUM21) located adjacent to the fumonisin polyketide synthase gene, FUM1. The presence of a Zn(II)2Cys6 DNA-binding domain in the predicted protein suggested that FUM21 was involved in transcriptional regulation. FUM21 deletion (Δfum21) mutants produce little to no fumonisin in cracked maize cultures but some FUM1 and FUM8 transcripts in a liquid GYAM medium. Complementation of a Δfum21 mutant with a wild-type copy of the gene restored fumonisin production. Analysis of FUM21 cDNAs identified four alternative splice forms (ASFs), and microarray analysis indicated the ASFs were differentially expressed. Based on these data, we present a model for how FUM21 ASFs may regulate fumonisin biosynthesis.


2012 ◽  
Vol 78 (12) ◽  
pp. 4468-4480 ◽  
Author(s):  
Lena Studt ◽  
Philipp Wiemann ◽  
Karin Kleigrewe ◽  
Hans-Ulrich Humpf ◽  
Bettina Tudzynski

ABSTRACTFusarium fujikuroiproduces a variety of secondary metabolites, of which polyketides form the most diverse group. Among these are the highly pigmented naphthoquinones, which have been shown to possess different functional properties for the fungus. A group of naphthoquinones, polyketides related to fusarubin, were identified inFusariumspp. more than 60 years ago, but neither the genes responsible for their formation nor their biological function has been discovered to date. In addition, although it is known that the sexual fruiting bodies in which the progeny of the fungus develops are darkly colored by a polyketide synthase (PKS)-derived pigment, the structure of this pigment has never been elucidated. Here we present data that link the fusarubin-type polyketides to a defined gene cluster, which we designatefsr, and demonstrate that the fusarubins are the pigments responsible for the coloration of the perithecia. We studied their regulation and the function of the single genes within the cluster by a combination of gene replacements and overexpression of the PKS-encoding gene, and we present a model for the biosynthetic pathway of the fusarubins based on these data.


2003 ◽  
Vol 47 (4) ◽  
pp. 1291-1296 ◽  
Author(s):  
Mikko Metsä-Ketelä ◽  
Kaisa Palmu ◽  
Tero Kunnari ◽  
Kristiina Ylihonko ◽  
Pekka Mäntsälä

ABSTRACT The biosynthesis pathways of two anthracyclines, nogalamycin and aclacinomycin, were directed toward angucyclines by using an angucycline-specific cyclase, pgaF, isolated from a silent antibiotic biosynthesis gene cluster. Addition of pgaF to a gene cassette that harbored the early biosynthesis genes of nogalamycin resulted in the production of two known angucyclinone metabolites, rabelomycin and its precursor, UWM6. Substrate flexibility of pgaF was demonstrated by replacement of the nogalamycin minimal polyketide synthase genes in the gene cassette with the equivalent aclacinomycin genes together with aknE2 and aknF, which specify the unusual propionate starter unit in aclacinomycin biosynthesis. This modification led to the production of a novel angucyclinone, MM2002, in which the expected ethyl side chain was incorporated into the fourth ring.


2016 ◽  
Vol 291 (53) ◽  
pp. 27403-27420 ◽  
Author(s):  
Slavica Janevska ◽  
Birgit Arndt ◽  
Eva-Maria Niehaus ◽  
Immo Burkhardt ◽  
Sarah M. Rösler ◽  
...  

2004 ◽  
Vol 70 (11) ◽  
pp. 6353-6362 ◽  
Author(s):  
Michelle C. Moffitt ◽  
Brett A. Neilan

ABSTRACT Nodularia spumigena is a bloom-forming cyanobacterium which produces the hepatotoxin nodularin. The complete gene cluster encoding the enzymatic machinery required for the biosynthesis of nodularin in N. spumigena strain NSOR10 was sequenced and characterized. The 48-kb gene cluster consists of nine open reading frames (ORFs), ndaA to ndaI, which are transcribed from a bidirectional regulatory promoter region and encode nonribosomal peptide synthetase modules, polyketide synthase modules, and tailoring enzymes. The ORFs flanking the nda gene cluster in the genome of N. spumigena strain NSOR10 were identified, and one of them was found to encode a protein with homology to previously characterized transposases. Putative transposases are also associated with the structurally related microcystin synthetase (mcy) gene clusters derived from three cyanobacterial strains, indicating a possible mechanism for the distribution of these biosynthetic gene clusters between various cyanobacterial genera. We propose an alternative hypothesis for hepatotoxin evolution in cyanobacteria based on the results of comparative and phylogenetic analyses of the nda and mcy gene clusters. These analyses suggested that nodularin synthetase evolved from a microcystin synthetase progenitor. The identification of the nodularin biosynthetic gene cluster and evolution of hepatotoxicity in cyanobacteria reported in this study may be valuable for future studies on toxic cyanobacterial bloom formation. In addition, an appreciation of the natural evolution of nonribosomal biosynthetic pathways will be vital for future combinatorial engineering and rational design of novel metabolites and pharmaceuticals.


2009 ◽  
Vol 99 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Erik Lysøe ◽  
Karen R. Bone ◽  
Sonja S. Klemsdal

The estrogenic mycotoxin zearalenone (ZON) produced by some Fusarium spp. causes reproductive problems and hyperestrogenic syndromes in mammals. In an effort to elucidate the molecular pathways of ZON production, we present a comparative real-time quantitative polymerase chain reaction expression study of seven contiguous genes in the ZON biosynthetic cluster on sterile rice and during wheat and oat infection. Under ZON production on rice, the polyketide synthase (PKS) genes PKS4 and PKS13, alcohol oxidase FG12056 gene, and transcriptional regulator FG02398 gene showed similarly upregulated patterns, whereas the nonribosomal peptide synthetase (NPS) FG02394, the K+ channel β subunit FG12015, and the protein kinase FG02399 displayed a variant pattern. During the same time period under wheat infection when no ZON was produced, the PKS genes and the NPS were downregulated relative to rice whereas the K+ channel β subunit gene FG12015 was markedly upregulated, suggesting that it may play a role in the infection process. This is the first expression study of ZON biosynthetic genes in planta. The results give insight into the regulation and activities of the ZON gene cluster under different experimental systems and suggest a connection between ZON and a K+ channel that could reveal a novel function for ZON in Fusarium spp.


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