| kanchanamycins, new polyol macrolide antibiotics produced by streptomyces olivaceus tii 4018. ii. structure elucidation. | kanchanamycins are a new group of polyol macrolide antibiotics isolated from streptomyces olivaceus tü 4018. they all share a common bicyclic carbon skeleton formed by a 36-membered lactone ring and a 6-membered hemiacetal ring. a feature unusual for that class of macrolides is the terminal urea moiety observed in kanchanamycin a. the structures of the kanchanamycins were determined by electrospray ms and modern 2d nmr techniques. due to substantial overlap of the signals intensive use of invers ... | 1996 | 8823508 |
| generation of hybrid elloramycin analogs by combinatorial biosynthesis using genes from anthracycline-type and macrolide biosynthetic pathways. | elloramycin and oleandomycin are two polyketide compounds produced by streptomyces olivaceus tü2353 and streptomyces antibioticus atcc11891, respectively. elloramycin is an anthracycline-like antitumor drug and oleandomycin a macrolide antibiotic. expression in s. albus of a cosmid (cos16f4) containing part of the elloramycin biosynthetic gene cluster produced the elloramycin non-glycosylated intermediate 8-demethyl-tetracenomycin c. several plasmid constructs harboring different gene combinatio ... | 2000 | 10937435 |
| identification of a sugar flexible glycosyltransferase from streptomyces olivaceus, the producer of the antitumor polyketide elloramycin. | elloramycin is an anthracycline-like antitumor drug related to tetracenomycin c which is produced by streptomyces olivaceus tü2353. structurally is a tetracyclic aromatic polyketide derived from the condensation of 10 acetate units. its chromophoric aglycon is glycosylated with a permethylated l-rhamnose moiety at the c-8 hydroxy group. only limited information is available about the genes involved in the biosynthesis of elloramycin. from a library of chromosomal dna from s. olivaceus, a cosmid ... | 2001 | 11306350 |
| cloning, sequencing, and heterologous expression of the elmghij genes involved in the biosynthesis of the polyketide antibiotic elloramycin from streptomyces olivaceus tü2353. | elloramycin a (1) belongs to a small family of naphthacenequinones characterized by a unique highly hydroxylated cyclohexenone moiety. a cosmid clone 16f4, harboring genes for the production of 1 from streptomyces olivaceus tü2353, has been previously isolated. dna sequence analysis of a 3.2-kb fragment from 16f4 revealed four open reading frames--the elmghij genes. heterologous expressions of the elmghi genes in either escherichia coli or streptomyces lividans, followed by biochemical character ... | 2001 | 11325225 |
| deoxysugar methylation during biosynthesis of the antitumor polyketide elloramycin by streptomyces olivaceus. characterization of three methyltransferase genes. | the anthracycline-like polyketide drug elloramycin is produced by streptomyces olivaceus tü2353. elloramycin has antibacterial activity against gram-positive bacteria and also exhibits antitumor activity. from a cosmid clone (cos16f4) containing part of the elloramycin biosynthesis gene cluster, three genes (elmmi, elmmii, and elmmiii) have been cloned. sequence analysis and data base comparison showed that their deduced products resembled s-adenosylmethionine-dependent o-methyltransferases. the ... | 2001 | 11376004 |
| digitoxosyltetracenomycin c and glucosyltetracenomycin c, two novel elloramycin analogues obtained by exploring the sugar donor substrate specificity of glycosyltransferase elmgt. | our explorations of glycosyltransferase elmgt from streptomyces olivaceus tü 2353, which shows an interesting flexibility regarding its sugar donor substrate, were extended toward various previously unexplored sugar co-substrates. the studies revealed that elmgt, which normally transfers l-rhamnose to 8-demethyltetracenomycin c as a crucial biosynthetic step in elloramycin biosynthesis, is also able to process an activated non-deoxygenated sugar, ndp-d-glucose, as well as ndp-l-digitoxose, which ... | 2002 | 12444703 |
| mycemycins a-e, new dibenzoxazepinones isolated from two different streptomycetes. | five new dibenzoxazepinone derivatives, mycemycins a-e (1-5), were isolated from the ethanol extracts of mycelia of two different streptomycetes. 1 and 2 were isolated from an acidic red soil-derived strain, streptomyces sp. fxj1.235, and 3-5 from a gntr gene-disrupted deep-sea strain named streptomyces olivaceus fxj8.012δ1741. the structures of mycemycins were elucidated by a combination of spectroscopic analyses, including 1d- and 2d-nmr techniques. | 2015 | 26437421 |
| biosynthesis of elloramycin in streptomyces olivaceus requires glycosylation by enzymes encoded outside the aglycon cluster. | elloramycin is an anthracycline-like antitumour drug produced by streptomyces olivaceus tü2353. cosmid cos16f4 has been previously shown to direct the biosynthesis of the elloramycin aglycon 8-demethyltetracenomycin c (8-dmtc), but not elloramycin. sequencing of the 24.2 kb insert in cos16f4 shows the presence of 17 genes involved in elloramycin biosynthesis (elm genes) together with another additional eight orfs probably not involved in elloramycin biosynthesis. the 17 genes would code for the ... | 2008 | 18310024 |
| modulation of deoxysugar transfer by the elloramycin glycosyltransferase elmgt through site-directed mutagenesis. | the glycosyltransferase elmgt from streptomyces olivaceus is involved in the biosynthesis of the antitumor drug elloramycin, and it has been shown to possess a broad deoxysugar recognition pattern, being able to transfer different l- and d-deoxysugars to 8-demethyl-tetracenomycin c, the elloramycin aglycone. site-directed mutagenesis in residues l309 and n312, located in the alpha/beta/alpha motif within the nucleoside diphosphate-sugar binding region, can be used to modulate the substrate flexi ... | 2009 | 19233921 |
| evidence for an iterative module in chain elongation on the azalomycin polyketide synthase. | the assembly-line synthases that produce bacterial polyketide natural products follow a modular paradigm in which each round of chain extension is catalysed by a different set or module of enzymes. examples of deviation from this paradigm, in which a module catalyses either multiple extensions or none are of interest from both a mechanistic and an evolutionary viewpoint. we present evidence that in the biosynthesis of the 36-membered macrocyclic aminopolyol lactones (marginolactones) azalomycin ... | 2016 | 27829923 |
| optimization of culture conditions for production of the anti-leukemic glutaminase free l-asparaginase by newly isolated streptomyces olivaceus neae-119 using response surface methodology. | among the antitumor drugs, bacterial enzyme l-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. glutaminase free l-asparaginase producing actinomycetes were isolated from soil samples collected from egypt. among them, a potential culture, strain neae-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16s rrna sequence as st ... | 2015 | 26180806 |
| screening of endophytic streptomycetes isolated from parthenium hysterophorus l. against nosocomial pathogens. | parthenium hysterophorus l. is an obnoxious weed of the family asteraceae recognized for its detrimental effects and significant economic losses to agriculture. in this study 42 endophytic streptomycetes strains were isolated from its roots and leaves. the isolates were identified by morphological, microscopic, biochemical and physiological characterization as members of genus streptomyces. in 16s rrna gene sequencing the selected isolates exhibited maximum similarity with streptomyces rochei (9 ... | 2013 | 23455197 |
| tandem expression in e. coli of type iii pks and p450 genes from marine streptomyces olivaceus fxj 7.023 gives production of phenol and indole. | the draft genome sequence of marine streptomyces olivaceus strain fxj 7.023 contains a cryptic type iii polyketide synthase (type iii pks) gene cluster, which is similar to the streptomyces coelicolor thn biosynthesis gene cluster. a putative type iii pks (sorppa) gene and its adjacent gene for cytochrome p450 158a2 (socyp158a2) of this gene cluster were cloned by pcr screening through a fosmid genomic library of s. olivaceus fxj 7.023. tandem expression of sorppa and socyp158a2 in escherichia c ... | 2015 | 25697286 |
| tetroazolemycins a and b, two new oxazole-thiazole siderophores from deep-sea streptomyces olivaceus fxj8.012. | two new oxazole/thiazole derivatives, named tetroazolemycins a (1) and b (2), have been isolated from the acetone extract of the mycelium of streptomyces olivaceus fxj8.012 derived from deep-sea water, together with three known compounds, spoxazomicins a-c (3-5), isolated from the fermentation supernatant. the planar structure and relative configuration of tetroazolemycins were elucidated by a combination of spectroscopic analyses, including 1d- and 2d-nmr techniques, and showed to be new pyoche ... | 2013 | 23665958 |
| biosynthesis, purification and characterization of β-1,4-xylanase from a novel mangrove associated actinobacterium streptomyces olivaceus (msu3) and its applications. | the present study was undertaken to evaluate the xylanolytic properties of an actinobacterium streptomyces olivaceus (msu3) isolated from the sediment sample of mangrove environment. it showed highest xylanase activity on initial screening in breg's mineral salts medium supplemented with 0.5% xylan. further the organism expressed maximum xylanase production at optimized culture conditions of ph 7, temperature 30 °c with 2.5% of inoculum size at 72 h of incubation, the nutrient sources like sucro ... | 2017 | 27693622 |
| cloning and identification of the lobophorin biosynthetic gene cluster from marine streptomyces olivaceus strain fxj7.023. | a full length about 105 kb gene cluster containing 35 open reading frames involved in the biosynthesis of lobophorins was cloned and sequenced from a fosmid genomic library of streptomyces olivaceus strain fxj7.023. the cluster was identified by genome wide annotation and analysis of secondary metabolite biosynthesis gene clusters by anti smash and knockout of loading module-contained region of polyketide skeleton synthesis gene (the starter of lobs1). gene cluster comparative analysis suggested ... | 2016 | 27005505 |