Chemical Characterisation of Disruptants of the Streptomyces coelicolor A3(2). ActVI Genes Involved in Actinorhodin Biosynthesis.

Taguchi, Tanezo; Itou, Keiko; Ebizuka, Yutaka; Malpartida, Francisco; Hopwood, David A.; Surti, Chandres M.; Booker‐Milburn, Kevin I.; Stephenson, G. R.; Ichinose, Koji

doi:10.7164/antibiotics.53.144

Cited by 61 publications

(68 citation statements)

References 27 publications

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“…Genome integration was confirmed by colony PCR with the primer set Neo-F and Neo-R for kanamycin-resistant clones as described by Ishikawa et al (2000). Transformants were liquid-cultured as described previously (Taguchi et al, 2000a). The medium separated from the broth by centrifugation was directly subjected to reversed-phase HPLC analysis on a TOSOH 8020 system under the following conditions: column, TSK gel ODS-80TM (4?6 mm i.d.…”

Section: Methodsmentioning

confidence: 99%

“…3). Our earlier experiments (Taguchi et al, 2000a) suggested the actVI-ORF2 protein, an enoyl reductase homologue, to function as the second reductase at C-15 to complete the (3S, 15R) configuration. The presence of another homologue, actVI-ORF4, prompted us to propose that the product might assist an unusual mode of reduction of (S)-DNPA (Taguchi et al, 2000a).…”

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 96%

“…Our earlier experiments (Taguchi et al, 2000a) suggested the actVI-ORF2 protein, an enoyl reductase homologue, to function as the second reductase at C-15 to complete the (3S, 15R) configuration. The presence of another homologue, actVI-ORF4, prompted us to propose that the product might assist an unusual mode of reduction of (S)-DNPA (Taguchi et al, 2000a). The reduction was proposed to proceed in two coupled steps, with stereospecific reduction (by ActVI-ORF2) of the double bond between C-14 and C-15 followed by isomerization (by ActVI-ORF4) to afford the a,b-unsaturated carbonyl structure, thus accomplishing the 1,4-reduction concerning C-15 and C-6.…”

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 96%

“…The phenotypic and chemical characterization of an actVI-ORF3 disruptant (Fernández-Moreno et al, 1992;Taguchi et al, 2000a) suggested that the product might catalyse chemically spontaneous processes such as the hemiketal formation and dehydration to afford (S)-DNPA (Fig. 3).…”

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 99%

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Cloning, sequencing and heterologous expression of the medermycin biosynthetic gene cluster of Streptomyces sp. AM-7161: towards comparative analysis of the benzoisochromanequinone gene clusters

et al. 2003

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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).

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Section: Methodsmentioning

confidence: 99%

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 96%

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 96%

Section: Post-pks Tailoring Steps In Aglycone Formationmentioning

confidence: 99%

See 2 more Smart Citations

Cloning, sequencing and heterologous expression of the medermycin biosynthetic gene cluster of Streptomyces sp. AM-7161: towards comparative analysis of the benzoisochromanequinone gene clusters

et al. 2003

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“…3) which are often found in experiments with streptomycetes mutants bearing manipulations in the cyclase functions of type II polyketide synthases (PKS) [6,7] and are under ongoing investigations [8]. In these experiments 2 and 3 turned out to be important key metabolites for the elucidation of the biosynthetic pathway of 4.…”

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confidence: 99%

Fogacin, a Novel Cyclic Octaketide Produced by Streptomyces Strain Tü 6319

et al. 2006

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A new octaketide named fogacin (1) was isolated from Streptomyces sp. (strain Tü 6319). Furthermore two shunt metabolites, SEK4b (2) and anhydroSEK4b (3), were detected and identified as nonenzymatically cyclized products of polyketide intermediates built during the biosynthesis of actinorhodin. SEK4b (2) as well as anhydroSEK4b (3) were previously described as metabolites of genetically engineered strains.Keywords polyketides, biosynthesis, shunt metabolites, SEK4b, HPLC screening Freshly isolated strains from soils collected at various sites in Romania were included in our HPLC-diode array screening program to detect novel secondary metabolites. Strain Tü 6319 which was isolated from an industrial contaminated soil near Fogaras, Romania, drew our attention because of its characteristic metabolite pattern, which appears analyzing the culture filtrate extract. Three of the metabolites were identified by means of our HPLC-UV-Vis database [2] as SEK4b (2) [3], and germicidins A and B [4], respectively. Two further metabolites did not correspond to any of the 834 reference compounds stored in our database. One of them was identified as anhydroSEK4b (3) [5], the second was named fogacin (1).Strain Tü 6319 was examined for a number of key properties known to be of value in streptomycete systematics. The presence of LL-diaminopimelic acid in the peptidoglycan together with its colonial characteristics allowed its assignment to the genus Streptomyces. Strain Tü 6319 shared a high 16S rRNA gene sequence with the closely related type strains Streptomyces coelescens DSM 40421, S. violaceolatus DSM 40438 and S. violaceoruber DSM 40049.Batch fermentation of strain Tü 6319 was carried out in 10-liter stirred tank fermenters (New Brunswick) in a medium that consisted of oat meal 2.0% in tap water (pH 7.3). The fermentation was conducted at 27°C for 168 hours with an aeration rate of 0.5 v/v/m and agitation of 200 rpm. Addition of 3% DMSO to the medium increased the production of 1 by 33%, reaching a maximum value of 10 mg/liter after 168 hours. Compound 1 was isolated from the culture filtrate (13 liters), loaded onto an Amberlite XAD-16 column (8ϫ40 cm) and eluted by increasing concentrations of MeOH. The 40% MeOH fraction that contained 1 was concentrated in vacuo, adjusted to pH 2, and extracted with ethyl acetate. The raw material was separated on a LiChroprep Diol column (2.6ϫ40 cm; Merck) applying a linear gradient CH 2 Cl 2 to a content of 5% MeOH within 3 hours at a flow rate of 5 ml/minute. A further metabolite (3) was separated from 1, and both compounds were purified by subsequent column chromatography on Sephadex LH-20 and Fractogel TSK HW-40 (each column 1.5ϫ90 cm, flow rate 15 ml/hour) using MeOH as eluent. Pure 1 was obtained in an amount of 8 mg.The antimicrobial activities of fogacin (1) and anhydro SEK4b (3) were examined by an agar plate diffusion assays. Compound 3 revealed a moderate inhibitory activity against Bacillus subtilis DSM 10 and

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Six‐Membered Rings, and Their Fused Derivatives

Diana

Cirrincione

2015

Biosynthesis of Heterocycles

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Chemical Characterisation of Disruptants of the Streptomyces coelicolor A3(2). ActVI Genes Involved in Actinorhodin Biosynthesis.

Cited by 61 publications

References 27 publications

Cloning, sequencing and heterologous expression of the medermycin biosynthetic gene cluster of Streptomyces sp. AM-7161: towards comparative analysis of the benzoisochromanequinone gene clusters

Cloning, sequencing and heterologous expression of the medermycin biosynthetic gene cluster of Streptomyces sp. AM-7161: towards comparative analysis of the benzoisochromanequinone gene clusters

Fogacin, a Novel Cyclic Octaketide Produced by Streptomyces Strain Tü 6319

Six‐Membered Rings, and Their Fused Derivatives

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