scholarly journals Transcriptome Analysis Identifies a Gene Cluster for the Biosynthesis of Biruloquinone, a Rare Phenanthraquinone, in a Lichen-Forming Fungus Cladonia macilenta

2021 ◽  
Vol 7 (5) ◽  
pp. 398
Author(s):  
Won-Yong Kim ◽  
Min-Hye Jeong ◽  
Sung-Hwan Yun ◽  
Jae-Seoun Hur

Lichens are prolific producers of natural products of polyketide origin. We previously described a culture of lichen-forming fungus (LFF) Cladonia macilenta that produces biruloquinone, a purple pigment that is a phenanthraquinone rarely found in nature. However, there was no genetic information on the biosynthesis of biruloquinone. To identify a biosynthetic gene cluster for biruloquinone, we mined polyketide synthase (PKS) genes from the genome sequence of a LFF isolated from thalli of C. macilenta. The 38 PKS in C. macilenta are highly diverse, many of which form phylogenetic clades with PKS previously characterized in non-lichenized fungi. We compared transcriptional profiles of the 38 PKS genes in two chemotypic variants, one producing biruloquinone and the other producing no appreciable metabolite in vitro. We identified a PKS gene (hereafter PKS21) that was highly upregulated in the LFF that produces biruloquinone. The boundaries of a putative biruloquinone gene cluster were demarcated by co-expression patterns of six clustered genes, including the PKS21. Biruloquinone gene clusters exhibited a high degree of synteny between related species. In this study we identified a novel PKS family responsible for the biosynthesis of biruloquinone through whole-transcriptome analysis.

2020 ◽  
pp. 153537022097301
Author(s):  
Charles L Phillips ◽  
Bradley A Welch ◽  
Michael R Garrett ◽  
Bernadette E Grayson

Peyer’s patches are gut-associated lymphoid tissue located throughout the intestinal wall. Peyer’s patches consist of highly organized ovoid-shaped follicles, classified as non-encapsulated lymphatic tissues, populated with B cells, T cells, macrophages, and dendritic cells and function as an organism’s intestinal surveillance. Limited work compares the gene profiles of Peyer’s patches derived from different intestinal regions. In the current study, we first performed whole transcriptome analysis using RNAseq to compare duodenal and ileal Peyer’s patches obtained from the small intestine of Long Evans rats. Of the 12,300 genes that were highly expressed, 18.5% were significantly different between the duodenum and ileum. Using samples obtained from additional subjects ( n = 10), we validated the novel gene expression patterns in Peyer’s patches obtained from the three regions of the small intestine. Rats had a significantly reduced number of Peyer’s patches in the duodenum in comparison to either the jejunum or ileum. Regional differences in structural, metabolic, and immune-related genes were validated. Genes such as alcohol dehydrogenase 1, gap junction protein beta 2, and serine peptidase inhibitor clade b, member 1a were significantly reduced in the ileum in comparison to other regions. On the other hand, genes such as complement C3d receptor type, lymphocyte cytosolic protein 1, and lysozyme C2 precursor were significantly lower in the duodenum. In summary, the gene expression pattern of Peyer’s patches is influenced by intestinal location and may contribute to its role in that segment.


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.


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.


2007 ◽  
Vol 52 (2) ◽  
pp. 574-585 ◽  
Author(s):  
Xiujun Zhang ◽  
Lawrence B. Alemany ◽  
Hans-Peter Fiedler ◽  
Michael Goodfellow ◽  
Ronald J. Parry

ABSTRACT The antibiotics lactonamycin and lactonamycin Z provide attractive leads for antibacterial drug development. Both antibiotics contain a novel aglycone core called lactonamycinone. To gain insight into lactonamycinone biosynthesis, cloning and precursor incorporation experiments were undertaken. The lactonamycin gene cluster was initially cloned from Streptomyces rishiriensis. Sequencing of ca. 61 kb of S. rishiriensis DNA revealed the presence of 57 open reading frames. These included genes coding for the biosynthesis of l-rhodinose, the sugar found in lactonamycin, and genes similar to those in the tetracenomycin biosynthetic gene cluster. Since lactonamycin production by S. rishiriensis could not be sustained, additional proof for the identity of the S. rishiriensis cluster was obtained by cloning the lactonamycin Z gene cluster from Streptomyces sanglieri. Partial sequencing of the S. sanglieri cluster revealed 15 genes that exhibited a very high degree of similarity to genes within the lactonamycin cluster, as well as an identical organization. Double-crossover disruption of one gene in the S. sanglieri cluster abolished lactonamycin Z production, and production was restored by complementation. These results confirm the identity of the genetic locus cloned from S. sanglieri and indicate that the highly similar locus in S. rishiriensis encodes lactonamycin biosynthetic genes. Precursor incorporation experiments with S. sanglieri revealed that lactonamycinone is biosynthesized in an unusual manner whereby glycine or a glycine derivative serves as a starter unit that is extended by nine acetate units. Analysis of the gene clusters and of the precursor incorporation data suggested a hypothetical scheme for lactonamycinone biosynthesis.


Microbiology ◽  
2003 ◽  
Vol 149 (7) ◽  
pp. 1633-1645 ◽  
Author(s):  
Koji Ichinose ◽  
Makoto Ozawa ◽  
Keiko Itou ◽  
Kanako Kunieda ◽  
Yutaka Ebizuka

Medermycin is a Streptomyces aromatic C-glycoside antibiotic classified in the benzoisochromanequinones (BIQs), which presents several interesting biosynthetic problems concerning polyketide synthase (PKS), post-PKS tailoring and deoxysugar pathways. The biosynthetic gene cluster for medermycin (the med cluster) was cloned from Streptomyces sp. AM-7161. Completeness of the clone was proved by the heterologous expression of a cosmid carrying the entire med cluster in Streptomyces coelicolor CH999 to produce medermycin. The DNA sequence of the cosmid (36 202 bp) revealed 34 complete ORFs, with an incomplete ORF at either end. Functional assignment of the deduced products was made for PKS and biosynthetically related enzymes, tailoring steps including strereochemical control, oxidation, angolosamine pathway, C-glycosylation, and regulation. The med cluster was estimated to be about 30 kb long, covering 29 ORFs. An unusual characteristic of the cluster is the disconnected organization of the minimal PKS genes: med-ORF23 encoding the acyl carrier protein is 20 kb apart from med-ORF1 and med-ORF2 for the two ketosynthase components. Secondly, the six genes (med-ORF14, 15, 16, 17, 18 and 20) for the biosynthesis of the deoxysugar, angolosamine, are all contiguous. Finally, the finding of a glycosyltransferase gene, med-ORF8, suggests a possible involvement of conventional C-glycosylation in medermycin biosynthesis. Comparison among the three complete BIQ gene clusters – med and those for actinorhodin (act) and granaticin (gra) – revealed some common genes whose deduced functions are unavailable from database searches (the ‘unknowns’). An example is med-ORF5, a homologue of actVI-ORF3 and gra-ORF18, which was highlighted by a recent proteomic analysis of S. coelicolor A3(2).


2020 ◽  
Vol 48 (22) ◽  
pp. e130-e130
Author(s):  
Chaoyi Song ◽  
Ji Luan ◽  
Ruijuan Li ◽  
Chanjuan Jiang ◽  
Yu Hou ◽  
...  

Abstract Biosynthesis reprograming is an important way to diversify chemical structures. The large repetitive DNA sequences existing in polyketide synthase genes make seamless DNA manipulation of the polyketide biosynthetic gene clusters extremely challenging. In this study, to replace the ethyl group attached to the C-21 of the macrolide insecticide spinosad with a butenyl group by refactoring the 79-kb gene cluster, we developed a RedEx method by combining Redαβ mediated linear-circular homologous recombination, ccdB counterselection and exonuclease mediated in vitro annealing to insert an exogenous extension module in the polyketide synthase gene without any extra sequence. RedEx was also applied for seamless deletion of the rhamnose 3′-O-methyltransferase gene in the spinosad gene cluster to produce rhamnosyl-3′-desmethyl derivatives. The advantages of RedEx in seamless mutagenesis will facilitate rational design of complex DNA sequences for diverse purposes.


2005 ◽  
Vol 71 (8) ◽  
pp. 4862-4871 ◽  
Author(s):  
Andreas Rascher ◽  
Zhihao Hu ◽  
Greg O. Buchanan ◽  
Ralph Reid ◽  
C. Richard Hutchinson

ABSTRACT Geldanamycin and the closely related herbimycins A, B, and C were the first benzoquinone ansamycins to be extensively studied for their antitumor properties as small-molecule inhibitors of the Hsp90 protein chaperone complex. These compounds are produced by two different Streptomyces hygroscopicus strains and have the same modular polyketide synthase (PKS)-derived carbon skeleton but different substitution patterns at C-11, C-15, and C-17. To set the stage for structural modification by genetic engineering, we previously identified the gene cluster responsible for geldanamycin biosynthesis. We have now cloned and sequenced a 115-kb segment of the herbimycin biosynthetic gene cluster from S. hygroscopicus AM 3672, including the genes for the PKS and most of the post-PKS tailoring enzymes. The similarities and differences between the gene clusters and biosynthetic pathways for these closely related ansamycins are interpreted with support from the results of gene inactivation experiments. In addition, the organization and functions of genes involved in the biosynthesis of the 3-amino-5-hydroxybenzoic acid (AHBA) starter unit and the post-PKS modifications of progeldanamycin were assessed by inactivating the subclusters of AHBA biosynthetic genes and two oxygenase genes (gdmM and gdmL) that were proposed to be involved in formation of the geldanamycin benzoquinoid system. A resulting novel geldanamycin analog, KOS-1806, was isolated and characterized.


Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1447
Author(s):  
Hisayuki Komaki ◽  
Natsuko Ichikawa ◽  
Akira Hosoyama ◽  
Moriyuki Hamada ◽  
Yasuhiro Igarashi

Micromonospora sp. TP-A0316 and Micromonospora sp. TP-A0468 are producers of arisostatin and kosinostatin, respectively. Micromonospora sp. TP-A0316 showed a 16S rRNA gene sequence similarity of 100% to Micromonosporaoryzae CP2R9-1T whereas Micromonospora sp. TP-A0468 showed a 99.3% similarity to Micromonospora haikouensis 232617T. A phylogenetic analysis based on gyrB sequences suggested that Micromonospora sp. TP-A0316 is closely related to Micromonospora oryzae whereas Micromonospora TP-A0468 is an independent genomospecies. As Micromonospora sp. TP-A0468 showed some phenotypic differences to its closely related species, it was classified as a novel species, for which the name Micromonospora okii sp. nov. is proposed. The type strain is TP-A0468T (= NBRC 110461T). Micromonospora sp. TP-A0316 and M. okii TP-A0468T were both found to harbor 15 gene clusters for secondary metabolites such as polyketides and nonribosomal peptides in their genomes. Arisostatin-biosynthetic gene cluster (BGC) of Micromonospora sp. TP-A0316 closely resembled tetrocarcin A-BGC of Micromonospora chalcea NRRL 11289. A large type-I polyketide synthase gene cluster was present in each genome of Micromonospora sp. TP-A0316 and M. okii TP-A0468T. It was an ortholog of quinolidomicin-BGC of M. chalcea AK-AN57 and widely distributed in the genus Micromonospora.


Sign in / Sign up

Export Citation Format

Share Document