branched-chain amino acid substitutions in the biosynthesis of the antibiotic actinomycin.actinomycins normally contain n-methyl-l-valine and either d-valine, d-alloisoleucine or both amino acids in the molecule. during antibiotic formation in a medium supplemented with one of the four isoleucine stereoisomers, streptomyces parvulus and s. chrysomallus form complex actinomycin mixtures (c(1), c(2), c(3), e(1), and e(2)-like compounds). although chromatographic techniques suggested that single homogeneous components had been isolated, subsequent studies indicated that such chromatogra ...197550761
genetic determination of methylenomycin synthesis by the scp1 plasmid of streptomyces coelicolor a3(2).evidence is presented that genes determining the pathway of methylenomycin a synthesis are carried on the scp1 plasmid. all 16 mutations (mmy) leading to lack of antibiotic synthesis were scp1-linked. phenotypic classification, by co-synthesis and other criteria, suggested that they fell into at least five classes. when the wild-type scp1 plasmid was transferred to streptomyces lividans or streptomyces parvulus, material that was chromatographically and biologically indistinguishable from methyl ...1977833570
high-frequency fusion of streptomyces parvulus or streptomyces antibioticus protoplasts induced by polyethylene glycol.conditions were established for the regeneration of protoplasts of streptomyces parvulus and streptomyces antibioticus to the mycelial form. regeneration was accomplished with a hypertonic medium that contained sucrose, cacl2, mgcl2, and low levels of phosphate. high-frequency fusion of protoplasts derived from auxotrophic strains of s. parvulus or s. antibioticus was induced by polyethylene glycol 4,000 (42%, wt/vol). the frequency of genetic transfer by the fusogenic procedure varied with the ...1979479112
cloning of the kanamycin resistance gene from a kanamycin-producing streptomyces species.a kanamycin-producing strain, streptomyces kanamyceticus isp5500, is resistant to kanamycin. a kanamycin resistance determinant was cloned from s. kanamyceticus into streptomyces lividans 1326, using the plasmid vector pij702. the resulting plasmid, pmcp5, could also transform streptomyces lavendulae s985 and streptomyces parvulus 2283 to kanamycin resistance. transformants carrying pmcp5 were markedly more resistant than s. kanamyceticus to the aminoglycoside antibiotics sisomicin, tobramycin, ...19846690428
the primary structure of alpha-amylase inhibitor z-2685 from streptomyces parvullus fh-1641. sequence homology between inhibitor and alpha-amylase.the native and oxidized alpha-amylase inhibitor z-2685, isolated from the culture medium of streptomyces parvullus fh-1641, and its overlapping cleavage products were degraded by the automatic edman technique. digestion was carried out with pepsin, thermolysin and trypsin. the alpha-amylase inhibitor is a polypeptide consisting of 76 amino acids with a molecular mass of 8 129 da. with the exception of methionine and lysine, all naturally occurring amino acids are present. it is interesting that ...19853879177
arylformamidase from streptomyces parvulus. 19872439878
actinomycin biosynthesis by protoplasts derived from streptomyces parvulus.conditions are described for the formation of protoplasts from streptomyces parvulus that are able to synthesize actinomycin d de novo. antibiotic synthesis by protoplasts, in contrast to that by mycelium, was sensitive to inhibition by actinomycin d and to a decrease in sucrose concentration. on the other hand, synthesis by mycelium was much more sensitive to inhibition by amino acid analogs (d-valine, cis-3-methylproline, and alpha-methyl-dl-tryptophan). in addition, the uptake of amino acids ...197875712
evidence for a constitutive and inducible form of kynurenine formamidase in an actinomycin-producing strain of streptomyces parvulus. 19806156659
the structure and biosynthesis of new tetrahydropyrimidine derivatives in actinomycin d producer streptomyces parvulus. use of 13c- and 15n-labeled l-glutamate and 13c and 15n nmr spectroscopy.two novel compounds, 2-methyl, 4-carboxy, 5-hydroxy-3,4,5,6-tetrahydropyrimidine (thp(a] and 2-methyl, 4-carboxy-3,4,5,6-tetrahydropyrimidine (thp(b] have been identified in the pool of streptomyces parvulus by in vivo and in vitro studies. 13c and 15n were introduced into the compounds by feeding s. parvulus with 15n- and 13c-labeled l-glutamate. high resolution 13c and 15n nmr have been applied to elucidate their structure and biosynthesis in s. parvulus. the splitting patterns and coupling co ...19882903148
the possible involvement of a plasmid(s) in actinomycin synthesis by streptomyces parvulus and streptomyces antibioticus.the treatment of streptomyces parvulus and streptomyces antibioticus with acriflavine or novobiocin resulted in the loss of ability to produce actinomycin. the concomitant loss of ability to form aerial mycelium and the incidence of auxotrophic progeny (s. parvulus) were both low relative to the loss of the antibiotic-producing property. protoplast fusion induced by polyethylene glycol 4000, using suitable auxotrophic strains of s. parvulus, resulted in high recombination frequencies to prototro ...197882552
13c nuclear magnetic resonance and gas chromatography-mass spectrometry studies of carbon metabolism in the actinomycin d producer streptomyces parvulus by use of 13c-labeled precursors.fructose and glutamate metabolism was monitored in cell suspensions of streptomyces parvulus by 13c nuclear magnetic resonance. the experiments were performed for cells grown with various 13c sources in a growth medium containing d-[u-13c]fructose, l-[13c]glutamate, or l-[u-13c]aspartate and with nonlabeled precursors to compare intracellular pools in s. parvulus cells at different periods of the cell life cycle. the transport of fructose into the cells was biphasic in nature; during rapid trans ...19911744035
novel actinomycins formed by biosynthetic incorporation of cis- and trans-4-methylproline.streptomyces parvulus (streptomyces parvullus) normally produces actinomycin d; in the presence of cis-4-methylproline, this species synthesizes two additional actinomycins, designated k(1c) and k(2c), in which one and two proline sites, respectively, are occupied by cis-4-methylproline. analogously, actinomycins k(1t) and k(2t) are formed in the presence of trans-4-methylproline. both mixtures were separated chromatographically, and the four novel actinomycins were obtained in crystalline form. ...197769418
purification and characterization of tryptophan dioxygenase from streptomyces parvulus.tryptophan dioxygenase, derived from streptomyces parvulus, was purified to near homogeneity and shown to have a native mr of 88,000. kinetic parameters of the enzyme were determined and evidence suggesting that it is a hemoprotein was obtained. tryptophan dioxygenase has a high specificity toward l-tryptophan with an apparent km of 0.3 mm. l-3-hydroxykynurenine was a competitive inhibitor with respect to l-tryptophan with a ki of 0.16 mm. in vitro, the enzyme displayed little activity in the ab ...19883341771
distinct kynureninase and hydroxykynureninase enzymes in an actinomycin-producing strain of streptomyces parvulus. 19806153909
structural analysis of loci involved in psam2 site-specific integration in streptomyces.psam2 is an 11-kb plasmid integrated in the streptomyces ambofaciens atcc23877 and atcc15154 genomes and found additionally as a free replicon in an uv derivative. after transfer into s. ambofaciens dsm40697 (devoid of psam2) or into streptomyces lividans, specific integration of psam2 occurred very efficiently. a 58-bp sequence (att) present in both psam2 (attp) and s. ambofaciens strain dsm40697 (attb) attachment regions is found at the boundaries (attl and attr) of integrated psam2 in s. ambo ...19892657820
control of actinomycin d biosynthesis in streptomyces parvullus: regulation of tryptophan oxygenase activity.tryptophan oxygenase (tryptophan 2,3-dioxygenase) activity increases immediately before the initiation of actinomycin d production by streptomyces parvullus. we have attempted to discern whether this increase is due to a release from catabolite repression or to the synthesis of an inducer substance. the standard culture medium (glutamic acid-histidine-fructose medium) used in antibiotic production studies with s. parvullus contains l-glutamate as a major constituent. l-glutamate is almost totall ...19816117549
the structure of manumycin. i. characterization, structure elucidation and biological activity.manumycin (1), produced by streptomyces parvulus (strain tü 64), was isolated from the mycelium by extraction with acetone and could easily be purified chromatographically. chemical degradation of 1 (c31h38n2o7) gave 2-acetamino-3-hydroxycyclopent-2-enone (2) by acetolysis, 2,4,6-trimethyl-2,4-decadienoic acid (3) by alkaline hydrolysis, and 2-(2,4,6-trimethyl-2,4-decadienoylamino)-5,6-epoxy-1,4-benzoquinon e (5) by chromic acid oxidation. in connection with a detailed spectroscopic analysis, th ...19873693123
overproduction, purification, and biochemical characterization of a xylanase (xys1) from streptomyces halstedii jm8.streptomyces halstedii jm8, isolated from straw, produces and secretes into the culture supernatant at least two proteins with hydrolytic activity towards xylan. the cloning of a dna fragment of this microorganism in several streptomyces strains permitted us to overproduce both proteins. n-terminal sequence analyses, immunoblot assays, and time course overproduction experiments allowed us to ensure that both xylanases were encoded by the same gene and that the smallest form (35 kda) originated f ...19957793962
the structure of manumycin. iii. absolute configuration and conformational studies.chromic acid oxidation of manumycin (1), an antibiotic produced by streptomyces parvulus (strain tü 64), led to the isolation of 2-(2-methyl-4-oxo-2-pentenoylamino)-5,6-epoxy-1,4-benzoquinone (3) and (-)-(r)-2-methylhexanoic acid (4). from the absolute configuration of 4, determined by comparing its optical rotation with published data, follows the absolute configuration at the center of chirality in the diene side chain of manumycin (1) to be (6'r). based on the direct comparison of the cd spec ...19873693125
genetic analysis of the actinomycin-producing determinants (plasmid) in streptomyces parvulus using the protoplast fusion technique.doubly auxotrophic, actinomycin-producing and nonproducing strains of streptomyces parvulus were crossed by protoplast fusion. a strong bias toward the act+ character was noted in all recombinant classes obtained. analysis of four nutritional markers revealed that they are ordered on a circular linkage map as follows: ura-lys-met-rib-(ura). this sequence resulted in the lowest frequency (2.4-3.4%) of quadruple crossover (qco) recombinants. inclusion of the property of actinomycin production in t ...19806165448
purification and characterization of kynurenine formamidase activities from streptomyces parvulus.two forms of kynurenine formamidase (ec; aryl-formylamine amidohydrolase) are present in extracts of streptomyces parvulus. the higher molecular weight enzyme (mr = 42 000), kynurenine formamidase i, appears to be constitutive and is present at relatively constant but low levels in antibiotic producing and nonproducing cultures, whereas the synthesis of the lower molecular weight form (mr = 25 000), kynurenine formamidase ii, is initiated just prior to the onset of actinomycin formation. ...19862425918
15n-nmr studies of living systems.15n-nmr spectroscopy has been applied to the study in vivo of nitrogen uptake during primary and secondary metabolism in streptomyces parvulus. the nitrogen metabolism of saccharomyces cerevisiae has been studied in a series of experiments in an effort to elucidate the flow of nitrogen along the various competing pathways as well as its dependence on culture conditions. the low nmr sensitivity of the 15n nucleus required, in spite of high isotopic enrichment, quite long acquisition times (10-20 ...19852424384
metabolites of microorganisms. 242 pyridindolol glucosides from streptomyces parvulus.from a new strain of streptomyces, streptomyces parvulus, strain tü 2480 three glucosides of the alkaloid pyridindolol were isolated. the structure elucidation is based on spectroscopic investigations and degradation to pyridindolol and alpha,d-methyl glucoside.19883366687
development of a chemically defined medium for the synthesis of actinomycin d by streptomyces parvulus.a chemically defined medium, consisting of d-fructose, l-glutamic acid, l-histidine, k(2)hpo(4), mgso(4).7h(2)o, znso(4).7h(2)o, cacl(2).2h(2)o, feso(4).7h(2)o, cocl(2).6h(2)o, and deionized water, was developed for synthesis of high yields (500 to 600 mug/ml) of actinomycin d by streptomyces parvulus. under these nutritional conditions, growth and actinomycin formation did not follow a typical trophophase-idiophase pattern. the amino acids appeared to have a sparing action on the utilization of ...1977848936
influence of increased dissolved oxygen concentration on the formation of secondary metabolites by manumycin-producing streptomyces parvulus.the influence of increased dissolved o2 concentrations (doc) on cell growth and production of the secondary metabolite manumycin by a strain of streptomyces parvulus (tü 64) was investigated in a stirred tank fermentor. doc is given as the o2 partial pressure (po2) in the gas phase in an equilibrium state with the liquid phase. growth of s. parvulus was not influenced up to doc equivalent to po2 = 1260 mbar. at po2 = 2205 mbar the maximum biomass concentration was lowered by 40%. production of m ...19947764965
site-specific integration of the actinophage r4 genome into the chromosome of streptomyces parvulus upon lysogenization.the lysogenization of streptomyces parvulus by actinophage r4 occurs by site-specific integration of the phage genome into the chromosome. the dna fragments containing the attachment sites on the host chromosome, the phage genome, and the two junctions created by insertion of the phage genome were cloned and sequenced. the attachment sites were found to share a common core of 12 bp. this common core sequence was not detected in chromosomal dnas of s. coelicolor and s. lividans.19912061298
metabolic regulation in streptomyces parvulus during actinomycin d synthesis, studied with 13c- and 15n-labeled precursors by 13c and 15n nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry.recent studies have suggested that the onset of synthesis of actinomycin d in streptomyces parvulus is due to a release from l-glutamate catabolic repression. in the present investigation we showed that s. parvulus has the capacity to maintain high levels of intracellular glutamate during the synthesis of actinomycin d. the results seem contradictory, since actinomycin d synthesis cannot start before a release from l-glutamate catabolic repression, but a relatively high intracellular pool of glu ...19883410824
molecular cloning of the whole biosynthetic pathway of a streptomyces antibiotic and its expression in a heterologous host.the application of molecular cloning to antibiotic-producing microorganisms should lead to enhanced antibiotic productivity and to the biosynthesis of novel antibiotics by in vitro interspecific recombination. to allow such approaches, the genes for antibiotic synthesis must be isolated, analysed and perhaps modified. certain streptomyces species produce nearly two-thirds of the known natural antibiotics; the recent development of cloning systems in the genus makes it possible to isolate and ana ...19846328317
electroporation of intact cells of streptomyces parvulus and streptomyces vinaceus.various assays of classical peg-assisted transformation as well as electrotransformation of streptomyces parvulus imet41380 and streptomyces vinaceus ncib8852 are described. contrary to the so far reported assays of electrotransforming streptomyces strains, electroporation in s. parvulus and s. vinaceus was carried out on intact cells, without any lysozyme treatment. in these two strains, the classical peg-assisted transformation of protoplasts does not work efficiently (10(3) to 10(4) transform ...19979228745
biosynthesis and characterization of [15n]actinomycin d and conformational analysis by nitrogen-15 nuclear magnetic resonance.we describe the production and characterization of actinomycin d labeled with 15n at all twelve nitrogen positions. cultures of streptomyces parvulus were incubated in the presence of racemic [15n]glutamic acid and, following an initial delay, labeled antibiotic was produced. evidence is presented that the d enantiomorph of glutamic acid was ultimately used for actinomycin biosynthesis. the 15n nmr spectrum at 10.14 and 20.47 mhz of the labeled drug in cdcl3 is presented. all nitrogens except th ...19826129895
protoplast fusion permits high-frequency transfer of a streptomyces determinant which mediates actinomycin synthesis.prototrophic recombinants and heterocaryotic colonies developed at high frequency when protoplasts of nutritionally complementary actinomycin-producing and nonproducing strains of streptomyces antibioticus were fused in the presence of polyethylene glycol and plated on minimal regeneration medium. of the spores obtained from aerial hyphae of a single heterocaryotic colony, 99% carried the act+ character regardless of whether the nutritional markers of the spore were derived from the act+ or the ...19826175616
conjugation and transformation of streptomyces species by tylosin resistance.the tlrb gene from streptomyces fradiae has been cloned and used to construct bifunctional streptomyces-escherichia coli shuttle vectors carrying the antibiotic resistance genes to kanamycin-neomycin, thiostrepton and tylosin as selection markers. in the same way, the tlrb gene was subcloned in plasmids including the apramycin resistance gene and the orit sequence from the plasmid pset152 to facilitate conjugation of streptomyces spores. the usefulness of the tlrb gene as tylosin resistance mark ...200010802191
control of the actinomycin biosynthetic pathway in and actinomycin resistance of streptomyces spp.using actinomycin-producing and nonproducing strains of streptomyces antibioticus, i studied several steps in the biosynthetic pathway of this antibiotic. actinomycin-nonproducing strains derived after acriflavine or novobiocin treatment showed activity of kynurenine formamidase and phenoxazinone synthase as high as that of the parental strain, but these nonproducing strains failed to convert 4-methyl-3-hydroxy-anthranilic acid to actinomycin. in addition, accumulation of 4-methyl-3-hydroxyanthr ...19826175617
integrated dna sequences in three streptomycetes form related autonomous plasmids after transfer to streptomyces lividans.when streptomyces parvulus atcc 12434 was crossed with a plasmid-free s. lividans 66 derivative, some s. lividans exconjugants contained plasmid dna, pij110 (13.6 kb). in a similar way, pij408 (15.05 kb) was found after mating s. glaucescens eth 22794 with s. lividans. ccc dna was not visualized in the donor strains. pij110 and pij408 each originates from a larger replicon, probably the chromosome, of s. parvulus or s. glaucescens. restriction maps of pij110 and pij408, each for 10 enzymes, were ...19846369354
biosynthesis of the angiogenesis inhibitor borrelidin by streptomyces parvulus tü4055: insights into nitrile formation.the 18-membered polyketide macrolide borrelidin exhibits a number of important biological activities, including potent angiogenesis inhibition. this has prompted two recent total syntheses as well as the cloning of the biosynthetic gene cluster from streptomyces parvulus tü4055. borrelidin possesses some unusual structural characteristics, including a cyclopentane carboxylic acid moiety at c17 and a nitrile moiety at c12 of the macrocyclic ring. nitrile groups are relatively rare in nature, and ...200415186422
antimicrobial potential of consolidation polymers loaded with biological copper nanoparticles.biodeterioration of historic monuments and stone works by microorganisms takes place as a result of biofilm production and secretion of organic compounds that negatively affect on the stone matrix.201627400968
complete genome sequence of streptomyces parvulus 2297, integrating site-specifically with actinophage r4.streptomyces parvulus 2297, which is a host for site-specific recombination according to actinophage r4, is derived from the type strain atcc 12434. species of s. parvulus are known as producers of polypeptide antibiotic actinomycins and have been considered for industrial applications. we herein report for the first time the complete genome sequence of s. parvulus 2297.201627563047
manumycin a induces apoptosis in malignant pleural mesothelioma through regulation of sp1 and activation of the mitochondria-related apoptotic pathway.manumycin a (manu a) is a natural product isolated from streptomyces parvulus and has been reported to have anti-carcinogenic and anti-biotic properties. however, neither its molecular mechanism nor its molecular targets are well understood. thus, the aim of the present study was to explore the possibility that manu a has cancer preventive and chemotherapeutic effects on malignant pleural mesothelioma (mpm) through regulation of sp1 and induction of mitochondrial cell death pathway. manu a inhib ...201627176604
the tylosin biosynthetic cluster from streptomyces fradiae: genetic organization of the left region.the genetic organization of the left edge (tyiedhfj region) of the tylosin biosynthetic gene cluster from streptomyces fradiae has been determined. sequence analysis of a 12.9 kb region has revealed the presence of 11 orfs, 10 of them belonging to the biosynthetic cluster. the putative functions of the proteins encoded by these genes are as follows: peptidase (orf1, ddca), tylosin resistance determinant (orf2, tlrb), glycosyltransferase (orf3, tyln), methyltransferase (orf4, tyle), ketoreductase ...199910220165
construction of a stepwise gene integration system by transient expression of actinophage r4 integrase in cyanobacterium synechocystis sp. pcc 6803.the integrase of actinophage r4, which belongs to the large serine-recombinase family, catalyzes site-specific recombination between two distinct attachment site sequences of the phage (attp) and actinomycete streptomyces parvulus 2297 chromosome (attb). we previously reported that r4 integrase (sre) catalyzed site-specific recombination both in vivo and in vitro. in the present study, a sre-based system was developed for the stepwise site-specific integration of multiple genes into the chromoso ...201424638932
cloning and sequences of two macrolide-resistance-encoding genes from mycinamicin-producing micromonospora griseorubida.two macrolide-resistance determinants were cloned from a mycinamicin (mm)-producing micromonospora griseorubida strain in streptomyces lividans and streptomyces parvulus. one of the cloned genes, designated myra, was cloned as a gene which conferred strong resistance to mm and tylosin (ty), but not to erythromycin (er) or josamycin (jm) on s. lividans. another gene, named myrb, was cloned as an err-encoding gene which conferred mls resistance (to macrolide, lincosamide and streptogramine b antib ...19948163173
the high resolution nmr structure of parvulustat (z-2685) from streptomyces parvulus fh-1641: comparison with tendamistat from streptomyces tendae 4158.the protein parvulustat (z-2685) from streptomyces parvulus comprises 78 amino acids and functions as a highly efficient alpha-amylase inhibitor. parvulustat shares 29.6 % overall amino acid sequence identity to the well-known alpha-amylase inhibitor tendamistat. among the conserved residues are the two disulfide bridges (c9-c25, c43-c70) and the active-site motif (w16, r17, y18). here, we report the high-resolution nmr structure of parvulustat based on noes, j couplings, chemical shifts and hyd ...200919067455
biosynthesis of the angiogenesis inhibitor borrelidin by streptomyces parvulus tü4055: cluster analysis and assignment of functions.the biosynthetic gene cluster for the angiogenesis inhibitor borrelidin has been cloned from streptomyces parvulus tü4055. sequence analysis indicates that the macrolide ring of borrelidin is formed by a modular polyketide synthase (pks) (bora1-a6), a result that was confirmed by disruption of bora3. the borrelidin pks is striking because only seven rather than the nine modules expected for a nonaketide product are encoded by bora1-a6. the starter unit of the pks has been verified as trans-cyclo ...200415112998
comparative studies on the primary structures and inhibitory properties of subtilisin-trypsin inhibitors from streptomyces.three novel proteinaceous inhibitors of serine proteases which had been identified as streptomyces subtilisin inhibitor-like (sil) inhibitors were isolated from culture supernatant of streptomyces; sil2 from streptomyces parvulus, sil3 from streptomyces coelicolor and sil4 from streptomyces lavendulae. they exhibited not only strong inhibitory activity toward subtilisin bpn' but also less strong inhibition of trypsin. their primary sequences were determined by sequence analysis of peptides obtai ...19948143745
the conformation of new tetrahydropyrimidine derivatives in solution and in the crystal.we have recently identified by nmr techniques two new tetrahydropyrimidine derivatives, 2-methyl-4-carboxy-5-hydroxy-3,4,5,6-tetrahydropyrimidine [thp(a)] and 2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine [thp(b)], which accumulated in actinomycin d producing streptomyces parvulus. their relatively high intracellular concentrations during actinomycin d synthesis and identity of the time of onset of their synthesis with that of actinomycin d synthesis leads us to suggest that they may function ...19938319696
studies on new dehydropeptidase inhibitors. i. taxonomy, fermentation, isolation and physico-chemical properties.ws1358a1 (fr104007) and b1 (fr104008), new potent inhibitors of renal dehydropeptidase, were isolated from the culture broth of strain no. 1358 which was identified as streptomyces parvulus subsp. in vitro inhibitory activities (ic50 value) of ws1358a1 and b1 against porcine renal dhp were 3 and 600 nm, respectively.19902307628
studies on new dehydropeptidase inhibitors. ii. structural elucidation and synthesis of ws1358a1 and b1.the structures of ws1358a1 and b1, new dehydropeptidase inhibitors isolated from streptomyces parvulus subsp. tochigiensis no. 1358, have been established to be 2-hydroxy-2-hydroxyaminocarbonyl-3-methylglutaric acid (1) and 2-hydroxy-2-hydroxyaminocarbonylglutaric acid (2), respectively, on the basis of spectroscopic evidence and synthesis of the racemates.19902307629
the sre gene (orf469) encodes a site-specific recombinase responsible for integration of the r4 phage genome.the sre gene (orf469) of the r4 phage encodes a protein similar to the resolvase-dna invertase family proteins. insertional gene disruption of sre prevented a lysogen from entering the lytic cycle, implying that sre protein is a site-specific recombinase needed for excision of the r4 prophage genome (m. matsuura, t. noguchi, t. aida, m. asayama, h. takahashi, and m. shirai, j. gen. appl. microbiol. 41:53-61, 1995). to determine whether this sre gene is also necessary for the integration reaction ...19968655526
cloning and nucleotide sequence of a xylanase-encoding gene from streptomyces sp. strain ec3.using the p1j702 vector, a xylanase-encoding gene (xin) of streptomyces sp. ec3 has been cloned by functional complementation of a mutant of streptomyces lividans tk24, producing xylanase at a very low level. normal level of xylanase synthesis was restored in at least three clones, containing the same 3802 bp sstl dna fragment. in this fragment, several open reading frames (orfs) have been identified, one of which coded for a xylanase; the products of the other orfs did not show homology with an ...19968722569
phage r4 integrase mediates site-specific integration in human cells.the r4 integrase is a site-specific, unidirectional recombinase derived from the genome of phage r4 of streptomyces parvulus. here we define compact attb and attp recognition sites for the r4 integrase and express the enzyme in mammalian cells. we demonstrate that r4 integrase functions in human cells, performing efficient and precise recombination between r4 attb and attp sites cloned on an extrachromosomal vector. we also provide evidence that the enzyme can mediate integration of an incoming ...200111707334
heterologous expression of an engineered biosynthetic pathway: functional dissection of type ii polyketide synthase components in streptomyces species.polyketides are an extensive class of secondary metabolites with diverse molecular structures and biological activities. a plasmid-based multicomponent polyketide synthase expression cassette was constructed using a subset of actinorhodin (act) biosynthetic genes (acti-orf1, acti-orf2, acti-orf3, actiii, actvii, and activ) from streptomyces coelicolor which specify the construction of the anthraquinone product aloesaponarin ii, a molecule derived from acetyl coenzyme a and 7 malonyl coenzyme a e ...19957868592
phenoxazinone biosynthesis: accumulation of a precursor, 4-methyl-3-hydroxyanthranilic acid, by mutants of streptomyces parvulus.mutants of streptomyces parvulus that are blocked in the synthesis of the phenoxazinone-containing antibiotic, actinomycin, were isolated by the 'agar piece' method (after ultraviolet irradiation or treatment with 8-methoxypsoralen plus near-ultraviolet light). radiolabelling experiments in conjunction with paper, thin-layer and column chromatography revealed that 4-methyl-3-hydroxyanthranilic acid (mha) is a major metabolite accumulated by these mutants. studies in vitro and in vivo provided ev ...1979458423
optimization of desferrioxamine e production by streptomyces parvulus.siderophores are produced by a number of microbes to capture iron with outstandingly high affinity, which property also generates biomedical and industrial interests. desferrioxamine e (dfo-e) secreted by streptomycetes bacteria can be an ideal candidate for iron chelation therapy, which necessitates its cost-effective production for in vitro and animal studies. this study focused on the optimization of dfo-e production by streptomyces parvulus cbs548.68. different combinations of various carbon ...201628033726
antitumor effect of the combination of manumycin a and immodin is associated with antiplatelet activity and increased granulocyte tumor infiltration in a 4t1 breast tumor model.manumycin a is a natural antibiotic isolated from streptomyces parvulus with broad range of biological activities including antineoplastic activity in several in vitro and in vivo cancer models. immodin [dialyzable leukocyte extract (dle)] is a dialysate released from disintegrated blood leukocytes of healthy donors which exerts immunonormalizing effects on cell-mediated immune responses. the aim of the present study was to explore the antitumor potential of the combination of manumycin a and im ...201727878284
antimicrobial activity and phylogenetic analysis of streptomyces parvulus dosmb-d105 isolated from the mangrove sediments of andaman islands.actinomycetes, especially species of streptomyces are prolific producers of pharmacologically significant compounds accounting for about 70% of the naturally derived antibiotics that are presently in clinical use. in this study, we used five solvents to extract the secondary metabolites from marine streptomyces parvulus dosmb-d105, which was isolated from the mangrove sediments of the south andaman islands. among them, ethyl acetate crude extract showed maximum activity against 11 pathogenic bac ...201627020867
occurrence and biosynthesis of c-demethylactinomycins in actinomycin-producing streptomyces chrysomallus and streptomyces parvulus.streptomyces chrysomallus and streptomyces parvulus produce novel c-demethylactinomycins besides their normal actinomycins when fed with 3-hydroxyanthranilic acid (3-ha). the 3-ha is incorporated into pentapeptide lactone precursors in competition with the regular precursor 4-methyl-3-hydroxyanthranilic acid (4-mha). the resultant 3-ha pentapeptide lactones can condense with each other, as well as with the continuously formed 4-mha pentapeptide lactones giving c-demethylactinomycins lacking one ...201323423168
streptomyces hyderabadensis sp. nov., an actinomycete isolated from soil.a novel actinomycete, designated strain ou-40(t), was isolated from farm soil collected from the hyderabad region of andhra pradesh, southern india. the strain was found to have morphological and chemotaxonomic characteristics typical of species of the genus streptomyces. phylogenetic analysis based on 16s rrna gene sequences indicated that strain ou-40(t) belonged to the genus streptomyces, and was related most closely to streptomyces pactum nbrc 13433(t) (99.0 % sequence similarity), streptomy ...201120154329
maldi-tof mass spectrometry, an efficient technique for in situ detection and characterization of extensive study of actinomycins was performed using matrix-assisted laser desorption/ionization mass spectrometry (maldi-tof ms). actinomycins represent a well-known family of peptidolactone chromopeptides with potent cytostatic and antibiotic properties. using five well-characterized streptomycete strains, we introduced maldi-tof ms as an efficient technique for rapid in situ detection of actinomycins in surface extracts of cells picked from agar plates. by this procedure, actinomycin comple ...201424619547
purification and characterization of a major collagenase from streptomyces parvulus.a major collagenase was purified about 96-fold from a crude enzyme sample of streptomyces parvulus by chromatography on q-sepharose, sephacryl s-200, and butyl-toyopearl. the purified enzyme showed a relative molecular mass of approximately 52,000 on sds-page and a ph optimum at about 9.0, and was strongly inhibited by metal-chelating agents. it also cleaved 4-phenylazobenzyloxycarbonyl-pro-leu-gly-pro-d-arg specifically at the leu-gly bond, with a k(m) value of 0.60 mm at ph 9.0 at 37 degrees c ...200919129667
characterization and biocontrol potent of streptomyces sp. isolated from the rhizosphere of ononis angustissima lam.a total of 40 actinomycetes isolated from rhizosphere soils of ononis angustissima lam. were in vitro tested for their antagonism against deferent pathogenic microorganisms by streak assay. among the isolates, four (21, 2a26, 1b10 and 2c34) present a potent antagonism against both pathogenic bacteria and fungi, they were selected, identified by 16s rdna sequence analysis and phenotypic properties, and tested for their antimicrobial activity as well as their biocontrol potential against chickpea ...201527141751
production of polypeptide antibiotic from streptomyces parvulus and its antibacterial activity.a highly potent secondary metabolite producing actinomycetes strain is isolated from marine soil sediments of visakhapatnam sea coast, bay of bengal. over all ten strains are isolated from the collected soil sediments. among the ten actinomycetes strains the broad spectrum strain rspsn2 was selected for molecular characterization, antibiotic production and its purification. the nucleotide sequence of the 1 rrna gene (1261 base pairs) of the most potent strain evidenced a 96% similarity with stre ...201424948949
production and characterization of protein encapsulated silver nanoparticles by marine isolate streptomyces parvulus ssnp11.production of protein encapsulated silver nanoparticles (agnps) assisted by marine actinomycetes strain has been investigated. the selective isolate was identified as streptomyces parvulus ssnp11 based on chemotaxonomic and 16s rrna analysis. maximum agnps production was observed within 24 h incubation time. the produced agnps are spherical in shape with monodispersive and crystalline in nature. the particle size distribution ranges from 1.66 to 11.68 nm with a mean size of 2.1 nm. the biosynthe ...201424891741
in vivo and in vitro characterization of site-specific recombination of actinophage r4 integrase.the site-specific integrase of actinophage r4 belongs to the serine recombinase family. during the lysogenization process, it catalyzes site-specific recombination between the phage genome and the chromosome of streptomyces parvulus 2297. an in vivo assay using escherichia coli cells revealed that the minimum lengths of the recombination sites attb and attp are 50-bp and 49-bp, respectively, for efficient intramolecular recombination. the in vitro assay using overproduced r4 integrases as a hexa ...201121478647
screening of actinomycetes from mangrove ecosystem for l-asparaginase activity and optimization by response surface methodology.marine actinomycetes were isolated from sediment samples collected from pitchavaram mangrove ecosystem situated along the southeast coast of india. maximum actinomycete population was noted in rhizosphere region. about 38% of the isolates produced l-asparaginase. one potential strain kua106 produced higher level of enzyme using tryptone glucose yeast extract medium. based on the studied phenotypic characteristics, strain kua106 was identified as streptomyces parvulus kua106. the optimization met ...201122184928
the conjugative plasmid slp2 of streptomyces lividans is a 50 kb linear molecule.the slp2 plasmid had previously been demonstrated genetically to exist in streptomyces lividans by its ability to promote conjugation and to elicit 'pocks' on recipient (slp2-) cultures, but it had not been physically detected. using pulsed-field gel electrophoresis, a 50 kb linear dna was isolated from slp2+ but not slp2- strains of s. lividans, and from streptomyces coelicolor and streptomyces parvulus strains to which slp2 had been transferred by conjugation or transformation. we conclude tha ...19938387146
high-performance liquid chromatographic assay validation of manumycin a in mouse plasma.manumycin a is a natural antibiotic produced by streptomyces parvulus that has antineoplastic activity against a variety of human cancers in nude mouse models. we have developed a highly sensitive reverse phase high-performance liquid chromatography (hplc) method based on ultraviolet (uv) detection for the determination of manumycin a in mouse plasma. manumycin a was isolated from mouse plasma by solid-phase extraction. a gradient elution of methanol and 0.05 m h(3)po(4) with 0.2% triethylamine ...200212137999
Partition Efficiency of High-Pitch Locular Multilayer Coil for Countercurrent Chromatographic Separation of Proteins Using Small-Scale Cross-Axis Coil Planet Centrifuge and Application to Purification of Various Collagenases with Aqueous-Aqueous Polymer Phase Systems.Partition efficiency of the high-pitch locular multilayer coil was evaluated in countercurrent chromatographic (CCC) separation of proteins with an aqueous-aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The separation column was specially made by high-pitch (ca 5 cm) winding of 1.0 mm I.D., 2.0 mm O.D. locular tubing compressed at 2 cm intervals with a total capacity of 29.5 mL. The protein separation was performed ...201121869859
enhanced antiproliferative and apoptotic response of ht-29 adenocarcinoma cells to combination of photoactivated hypericin and farnesyltransferase inhibitor manumycin a.several photodynamically-active substances and farnesyltransferase inhibitors are currently being investigated as promising anticancer drugs. in this study, the combined effect of hypericin (the photodynamically-active pigment from hypericum perforatum) and selective farnesyltransferase inhibitor manumycin (manumycin a; the selective farnesyltransferase inhibitor from streptomyces parvulus) on ht-29 adenocarcinoma cells was examined. we found that the combination treatment of cells with photoact ...201122272079
heterologous production of polyketides by modular type i polyketide synthases in escherichia coli.heterologous production of polyketide compounds, an important class of natural products with complex chemical structures, was first demonstrated with streptomyces parvulus in 1984. although streptomyces strains are good first options for heterologous polyketide biosynthesis, their slow growth kinetics prompt other hosts to also be considered. escherichia coli provides key elements of an ideal host in terms of the growth rate, culture conditions, and available recombinant dna tools. here we revie ...201222244790
antimicrobial potential of actinobacteria isolated from the rhizosphere of the caatinga biome plant caesalpinia pyramidalis tul.actinobacteria are known to produce various secondary metabolites having antibiotic effects. this study assessed the antimicrobial potential of actinobacteria isolated from the rhizosphere of caesalpinia pyramidalis tul. from the caatinga biome. sixty-eight actinobacteria isolates were evaluated for antimicrobial activity against different microorganisms by disk diffusion and submerged fermentation, using different culture media, followed by determination of minimum inhibitory concentration (mic ...201626985927
streptomyces-derived actinomycin d inhibits biofilm formation by staphylococcus aureus and its hemolytic activity.staphylococcus aureus is a versatile human pathogen that produces diverse virulence factors, and its biofilm cells are difficult to eradicate due to their inherent ability to tolerate antibiotics. the anti-biofilm activities of the spent media of 252 diverse endophytic microorganisms were investigated using three s. aureus strains. an attempt was made to identify anti-biofilm compounds in active spent media and to assess their anti-hemolytic activities and hydrophobicities in order to investigat ...201626785934
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