| transfection in streptomyces virginiae [proceedings]. | | 1977 | 913841 |
| pesticidal activity of virginiamycins s1 and m1. | virginiamycins s1 and m1, two major components of the antibacterial antibiotic complex produced by streptomyces virginiae and used as an animal growth promoter in animal husbandry, exhibited a selective insecticidal activity against leptinotarsa decemlineata comparable with the effect of the organophosphorus pesticide metathion. an acaricidal effect of the two compounds on eggs of tetranychus urticae was also observed. | 1992 | 1493906 |
| new virginiae butanolides from streptomyces virginiae. | | 1989 | 2621168 |
| the structure of inducing factors for virginiamycin production in streptomyces virginiae. | virginiamycin inducing factors (inducing material or inducing factor) of streptomyces virginiae were isolated from the culture broth of this microbe and separated into three closely related compounds. they were named virginiae butanolides a, b and c and their structures were determined as 2-(1'-hydroxy-5'-methylhexyl)-3-(hydroxymethyl)butanolide (6), 2-(1'-hydroxy-4'-methylhexyl)-3-(hydroxymethyl)butanolide (7) and 2-(1'-hydroxyhexyl)-3-(hydroxymethyl)butanolide (8), respectively. part of their ... | 1987 | 3108224 |
| a41030, a complex of novel glycopeptide antibiotics produced by a strain of streptomyces virginiae. taxonomy and fermentation studies. | a41030 is a complex of novel glycopeptide antibiotics produced by a culture isolated from a soil. taxonomic studies have identified the microorganism, nrrl 15156, as a strain of streptomyces virginiae. the major factor, a41030a, and three of the six minor factors are unique among glycopeptides in that they are naturally occurring aglycones, containing no neutral or amino sugars. the a41030 that was not spontaneously released into the fermentation broth could be released from the biomass into aqu ... | 1985 | 3838299 |
| pfj265, a new cloning vehicle for streptomyces. | a 9.3-kb plasmid, pnm100, was isolated from streptomyces virginiae (nrrl 15156) and characterized. streptomyces genes for thiostrepton and neomycin resistance were cloned into pnm100 to yield a small plasmid derivative, pfj265, that is suitable for streptomyces gene cloning. pfj265 is a 9.2-kb nonconjugative plasmid and has a copy number of several hundred per chromosome. | 1984 | 6324262 |
| gene organization in the ada-rpll region of streptomyces virginiae. | the gene organization of a 7.4-kb region of the streptomyces virginiae (sv) chromosome was determined. the predicted open reading frames (orfs) and their predicted products, in sequence order, were (i) ada, encoding adenosine deaminase [ec 3.5.4.4], (ii) aat, encoding a protein homologous to aspartate aminotransferase [ec 2.6.1.1], (iii) sece, encoding a protein involved in protein secretion, (iv) vbra, encoding a nusg-like protein involved in antitermination of transcription as described by oka ... | 1996 | 8675024 |
| [molecular genetic study of the strain streptomyces virginiae-- the producer of virginiamycin]. | the level and the character of the streptomyces virginiae virginiamycin-producing strain's resistance to self-produced antibiotic and a number of antibiotics from different groups were determined. s. virginiae was shown to display constitutive and inducible resistance to self-produced antibiotic. the phenomenon of cross-inducible resistance of the strain to virginiamycin and the antibiotics erythromycin, oleandomycin, and thiostrepton was demonstrated. the pto1 and pvgtb24 plasmids were introduc ... | 1996 | 8754065 |
| stereospecific reduction of virginiamycin m1 as the virginiamycin resistance pathway in streptomyces virginiae. | in a cell extract of streptomyces virginiae, virginiamycin m1 was inactivated in the presence of nadph, while virginiamycin s remained intact. the inactivated product of virginiamycin m1 was isolated, and structure analysis revealed that the inactivation involves reduction of a c-16 carbonyl group leading to the formation of 16-dihydrovirginiamycin m1. acetonide and benzylidene acetal derivatives were synthesized from the two hydroxyl groups on c-14 and c-16, and the c-16 stereochemistry was det ... | 1996 | 8851577 |
| butyrolactone autoregulator receptor protein (bara) as a transcriptional regulator in streptomyces virginiae. | bara of streptomyces virginiae is a specific receptor protein for virginiae butanolides (vbs), a member of the butyrolactone autoregulators of streptomyces species. sequencing around the bara gene revealed two novel open reading frames: one upstream, barx, encoding a homolog of afsa of streptomyces griseus and another downstream, barb. northern (rna) blot analysis for s. virginiae demonstrated that the addition of vb during cultivation switched on the expression of barb. an in vivo expression sy ... | 1997 | 9371444 |
| identification and in vivo functional analysis of a virginiamycin s resistance gene (vars) from streptomyces virginiae. | bara of streptomyces virginiae is a specific receptor protein for virginiae butanolide (vb), one of the gamma-butyrolactone autoregulators of the streptomyces species, and acts as a transcriptional regulator controlling both virginiamycin production and vb biosynthesis. the downstream gene barb, the transcription of which is under the tight control of the vb-bara system, was found to be transcribed as a polycistronic mrna with its downstream region, and dna sequencing revealed a 1,554-bp open re ... | 1999 | 10322037 |
| identification by gene deletion analysis of a regulator, vmsr, that controls virginiamycin biosynthesis in streptomyces virginiae. | virginiae butanolide (vb)-bara of streptomyces virginiae is one of the newly discovered pairs of a butyrolactone autoregulator and a corresponding receptor protein of streptomyces species and regulates the production of the antibiotic virginiamycin (vm) in s. virginiae. the gene vmsr was found to be situated 4.7 kbp upstream of the bara gene, which encodes the vb-specific receptor. the vmsr product was predicted to be a regulator of vm biosynthesis based on its high homology to some streptomyces ... | 2000 | 11029453 |
| streptogramin b biosynthesis in streptomyces pristinaespiralis and streptomyces virginiae: molecular characterization of the last structural peptide synthetase gene. | streptomyces pristinaespiralis and s. virginiae both produce closely related hexadepsipeptide antibiotics of the streptogramin b family. pristinamycins i and virginiamycins s differ only in the fifth incorporated precursor, di(mono)methylated amine and phenylalanine, respectively. by using degenerate oligonucleotide probes derived from internal sequences of the purified s. pristinaespiralis snbd and snbe proteins, the genes from two streptogramin b producers, s. pristinaespiralis and s. virginia ... | 1997 | 9303382 |
| bars1, a gene for biosynthesis of a gamma-butyrolactone autoregulator, a microbial signaling molecule eliciting antibiotic production in streptomyces species. | from streptomyces virginiae, in which production of streptogramin antibiotic virginiamycin m(1) and s is tightly regulated by a low-molecular-weight streptomyces hormone called virginiae butanolide (vb), which is a member of the gamma-butyrolactone autoregulators, the hormone biosynthetic gene (bars1) was cloned and characterized by heterologous expression in escherichia coli and by gene disruption in s. virginiae. the bars1 gene (a 774-bp open reading frame encoding a 257-amino-acid protein [m( ... | 2002 | 12193632 |
| a gene cloning system for 'streptomyces toyocaensis'. | we explored different methods of introducing dna into 'streptomyces toyocaensis' and streptomyces virginiae to construct stable recombinant strains. plasmid pij702 isolated from streptomyces lividans transformed protoplasts of 's. toyocaensis' at a frequency of 7 x 10(3) transformants (mu g dna)-1. pij702 prepared from 's. toyocaensis' transformed 's. toyocaensis' protoplasts at a frequency of 1 center dot 5 x 10(5) (mu g dna)-1, suggesting that 's. toyocaensis' expresses restriction and modific ... | 1996 | 8932699 |
| properties of a bacteriocin-like substance produced by streptomyces virginiae. | | 1964 | 14160072 |
| distribution in the genus streptomyces of a homolog to nusg, a gene encoding a transcriptional antiterminator. | the presence of the vbra gene encoding the transcriptional antiterminator nusg equivalent protein of streptomyces virginiae was tested for in 73 streptomyces species by southern hybridization. fifty-five strains (75%) including s. griseus, s. lividans tk-21 and s. coelicolor a3(2) showed clear hybridization signals, indicating wide distribution of vbra or vbra homologs in streptomyces species. with hybridization patterns against 3 different probes, i.e., probes covering vbra alone, the downstrea ... | 1993 | 8349097 |
| phenotypic and genotypic characterization of mutants of the virginiamycin producing strain 899 and its relatedness to the type strain of streptomyces virginiae. | a representative set of 19 mutants, with a known genealogy, of the virginiamycin producing strain streptomyces virginiae 899 was investigated phenotypically and genotypically. colour of the aerial and substrate mycelium were very variable both among spontaneous variants and those obtained after induced mutagenesis. at genotypic level, all mutants showed nearly identical box patterns, not reflecting the phenotypic heterogeneity observed. more than 40 years of forced mutational pressure did not ca ... | 2005 | 15709368 |
| a null mutant of the streptomyces virginiae bara gene encoding a butyrolactone autoregulator receptor and its phenotypic and transcriptional analysis. | the streptomyces virginiae bara gene encodes a specific receptor protein for virginiae butanolide (vb), one of the gamma-butyrolactone autoregulators of streptomyces species. by homologous recombination, a bara null strain was constructed to clarify the in vivo function of bara protein in s. virginiae. the deltabara mutant showed no difference in terms of growth, but lost vb production and produced virginiamycin 7 h earlier than the wild-type strain. these results indicated that, phenotypically, ... | 2000 | 16232843 |
| organization and nucleotide sequence of the sece-nusg region of streptomyces griseus. | the nusg genes of streptomyces griseus and streptomyces coelicolor a3(2) were cloned by the dna-probing method with synthetic oligonucleotides designed on the basis of the nucleotide sequence of the nusg gene of streptomyces virginiae. the amino acid sequences of the nusg proteins deduced from the nucleotide sequences showed significant homologies to those from a variety of microorganisms. nucleotide sequence analysis of the region upstream of the nusg gene of s. griseus revealed the presence of ... | 1994 | 8286423 |
| application of the random amplified polymorphic dna using the polymerase chain reaction for efficient elimination of duplicate strains in microbial screening. ii. actinomycetes. | we evaluated the random amplified polymorphic dna (rapd) method using streptomyces lavendulae and streptomyces virginiae strains to eliminate duplicate actinomycete strains in our microbial screening program. the rapd data were compared with phenotypic characteristics, dna relatedness, hplc analysis of metabolites and low-frequency restriction fragment analysis by pulsed-field gel electrophoresis. these results were consistent with each other. therefore, we conclude that rapd is a simple, effici ... | 1994 | 8150714 |
| primary structure and inhibitory properties of a subtilisin-chymotrypsin inhibitor from streptomyces virginiae. | a novel serine protease inhibitor sil8, which was isolated from the culture medium of streptomyces virginiae and shown to be a member of the streptomyces subtilisin-inhibitor-like (sil) inhibitor family by sequence analysis of its amino-terminal region [taguchi, s., kikuchi, h., kojima, s., kumagai, i., nakase, t., miura, k. & momose, h. (1993) biosci. biotech. biochem. 57, 522-524], is the first sil inhibitor demonstrated to show marked inhibitory activity toward alpha-chymotrypsin, in addition ... | 1994 | 8001578 |
| identification of the bkdab gene cluster, a plausible source of the starter-unit for virginiamycin m production in streptomyces virginiae. | the bkdab gene cluster, which encodes plausible e1 and e2 components of the branched-chain alpha-keto acid dehydrogenase (bcdh) complex, was isolated from streptomyces virginiae in the vicinity of a regulatory island for virginiamycin production. gene disruption of bkda completely abolished the production of virginiamycin m (a polyketide-peptide antibiotic), while the production of virginiamycin s (a cyclodepsipeptide antibiotic) was unaffected. complementation of the bkda disruptant by genome-i ... | 2007 | 17375285 |
| biotransformation of diosgenin to nuatigenin-type steroid by a newly isolated strain, streptomyces virginiae ibl-14. | an actinomycete strain ibl-14 isolated from soil by utilizing diosgenin as the sole carbon and energy source was identified as streptomyces virginiae. s. virginiae ibl-14 can transform diosgenin to isonuatigenone. to our knowledge, this is the first reported case of producing rare nuatigenin-type spirosteroid (isonuatigenone) from pyrano-spirosteroid (diosgenin) by microbial transformation. from diosgenin to isonuatigenone, the pathway has been confirmed in this study that diosgenin was first co ... | 2007 | 17955193 |
| virginiae butanolide binding protein from streptomyces virginiae. evidence that vbra is not the virginiae butanolide binding protein and reidentification of the true binding protein. | virginiae butanolides (vbs) a-e are butyrolactone autoregulators that control virginiamycin production in streptomyces virginiae. we have previously reported the purification and molecular cloning of vbra, a putative vb binding protein (okamoto, s., nihira, t., kataoka, h., suzuki, a., and yamada, y. (1992) j. biol. chem. 267, 1093-1098). however, vbra protein overexpressed in escherichia coli did not show any detectable vb binding activity nor did the immunoprecipitation of native vbra from a c ... | 1995 | 7744885 |
| optimum autoregulator addition strategy for maximum virginiamycin production in batch culture of streptomyces virginiae. | virginiae butanolides (vbs) are autoregulators of streptomyces virginiae, which induce virginiamycin biosynthesis. generally, autoregulators are synthesized by the microorganism itself during culture. addition of chemically synthesized virginiae butanolide-c (vb-c), which is one of the vbs, can also control the induction time and the amount of virginiamycin production. the optimum concentration and shot-feeding time of vb-c for the maximum production of virginiamycins m and s were investigated i ... | 1995 | 18623335 |
| isolation and characterization of a41030, a complex of novel glycopeptide antibiotics. application of the michel-miller high performance low pressure liquid chromatography system. | a new antibiotic complex, designated a41030, has been isolated from the fermentation broth of streptomyces virginiae. factors a, b, c, d, e, f and g were separated by an efficient preparative high performance low pressure liquid chromatography system. the apparatus offers economic reversed phase separations on glass columns. the a41030 factors are members of the general class of glycopeptide antibiotics and are active in vitro and in vivo vs. gram-positive bacteria. | 1986 | 3755427 |
| structure-activity relationships of virginiae butanolide c, an inducer of virginiamycin production in streptomyces virginiae. | virginiae butanolide c, [2-(1'-hydroxyhexyl)-3-(hydroxymethyl)butanolide (3)], is one of the inducers of virginiamycin production in streptomyces virginiae. various racemic analogues were synthesized, and their effectiveness in virginiamycin induction was studied. among analogues having a series of c-2 side chains, those with 1'-hydroxyheptyl or 1'-hydroxyoctyl moiety were most effective with a minimum effective concentration of 0.8 ng/ml. at the same length of c-2 side chain, a 2,3-cis analogue ... | 1988 | 3145258 |
| characterization of p450 fcpc, the enzyme responsible for bioconversion of diosgenone to isonuatigenone in streptomyces virginiae ibl-14. | a new cytochrome p450 monooxygenase, fcpc, from streptomyces virginiae ibl-14 has been identified. this enzyme is found to be responsible for the bioconversion of a pyrano-spiro steroid (diosgenone) to a rare nuatigenin-type spiro steroid (isonuatigenone), which is a novel c-25-hydroxylated diosgenone derivative. a whole-cell p450 system was developed for the production of isonuatigenone via the expression of the complete three-component electron transfer chain in an escherichia coli strain. | 2009 | 19376895 |
| detection and properties of a-factor-binding protein from streptomyces griseus. | the optically active form of tritium-labeled a-factor (2-isocapryloyl-3r-hydroxymethyl-gamma-butyrolactone), a pleiotropic autoregulator responsible for streptomycin production, streptomycin resistance, and sporulation in streptomyces griseus, was chemically synthesized. by using the radioactive a-factor, a binding protein for a-factor was detected in the cytoplasmic fraction of this organism. the binding protein had an apparent molecular weight of approximately 26,000, as determined by gel filt ... | 1989 | 2502536 |
| identification of binding protein of virginiae butanolide c, an autoregulator in virginiamycin production, from streptomyces virginiae. | in streptomyces virginiae, production of virginiamycin is triggered by signal molecules named virginiae butanolide a, b or c (vb-a, b or c: yamada, y. et al. j. antibiotics 40: 496-504, 1987). we have found a specific vb-c binding protein from s. virginiae, and characterized it by using a tritium-labeled vb-c analogue as a ligand. by equilibrium dialysis in the absence and presence of radio-inert vb-c, a crude extract from 1 g of wet mycelia specifically bound 3.5 pmol of [3h]vb. the binding dis ... | 1989 | 2498276 |
| purification and characterization of virginiae butanolide c-binding protein, a possible pleiotropic signal-transducer in streptomyces virginiae. | virginiae butanolide c (vb-c) is an autoregulator which triggers virginiamycin production in streptomyces virginiae. a new binding assay with tritium-labeled vb-c analogue (2,3-cis-2-(1'-hydroxy-[6',7'-3h]heptyl)-3-(hydroxymethyl)butanolide+ ++ ) was developed and a specific vb-c binding protein was purified to homogeneity from crude extracts of s. virginiae by ammonium sulfate fractionation, deae-sephacel and sephadex g-100 column chromatographies, hydrophobic hplc on phenyl 5pw and native pol ... | 1990 | 2380115 |
| crystallization and preliminary crystallographic studies of the butyrolactone autoregulator receptor protein (bara) from streptomyces virginiae. | the streptomyces butyrolactone autoregulator receptor protein (bara) is a dna-binding protein that regulates the biosynthesis of the antibiotic virginiamycin. in this study, bara from s. virginiae was overexpressed in escherichia coli, purified and crystallized. crystals of purified protein have been grown that diffracted to beyond 3.0 a resolution at 100 k using synchrotron radiation. the protein crystals belonged to the hexagonal space group p6(5)22, with unit-cell parameters a = b = 128.0, c ... | 2010 | 20516594 |
| taxonomic studies of streptomyces virginiae mutants overproducing virginiamycin m1. | by using both the traditional international streptomycetes project methods and chemical approaches followed by a hierarchical cluster analysis, streptomyces virginiae mutants a-1 and b-43 (yielding higher amounts of the m1 component of virginiamycin complex), their wild ancestor atcc 13161, and another virginiamycin producer, s. pristinaespiralis nrrl 2958, were subjected to taxonomic studies to find kinship or differences among the strains. of the methods used, only the test of carbon utilizati ... | 1992 | 1505866 |
| pleiotropic control of secondary metabolism and morphological development by ksbc, a butyrolactone autoregulator receptor homologue in kitasatospora setae. | the γ-butyrolactone autoregulator signaling cascades have been shown to control secondary metabolism and/or morphological development among many streptomyces species. however, the conservation and variation of the regulatory systems among actinomycetes remain to be clarified. the genome sequence of kitasatospora setae, which also belongs to the family streptomycetaceae containing the genus streptomyces, has revealed the presence of three homologues of the autoregulator receptor: ksba, which has ... | 2012 | 22961899 |
| on-line biomass monitoring by capacitance measurement. | an in-situ, steam-sterilizable capacitance probe was used to follow the biomass concentration on-line, in bioreactors from 20 to 2000 l total volume. microbial cultures of saccharomyces cerevisiae, pichia pastoris and streptomyces virginiae were grown in batch and fed-batch culture in both defined and complex media in order to demonstrate the wide dynamic operating range of the instrument. a linear correlation was found between the on-line capacitance measurement and the off-line measurements (o ... | 1992 | 1368248 |
| purification and molecular cloning of a butyrolactone autoregulator receptor from streptomyces virginiae. | in streptomyces, low molecular weight compounds termed "autoregulators" have been isolated as primary signal molecules for triggering secondary metabolism and/or cytodifferentiation. streptomyces virginiae produces a set of autoregulators termed virginiae butanolide a-e which trigger virginiamycin production, and possesses a high-affinity virginiae butanolide receptor (kim, h.s., nihira, t., tada, h., yanagimoto, m., and yamada, y. (1989) j. antibiot. (tokyo) 42, 769-778). the virginiae butanoli ... | 1992 | 1309760 |
| identification by heterologous expression and gene disruption of visa as l-lysine 2-aminotransferase essential for virginiamycin s biosynthesis in streptomyces virginiae. | the visa gene of streptomyces virginiae has been thought to be a part of the virginiamycin s (vs) biosynthetic gene cluster based on its location in the middle of genes that encode enzymes highly similar to those participating in the biosynthesis of streptogramin-type antibiotics. heterologous expression of the visa gene was achieved in escherichia coli by an n-terminal fusion with thioredoxin (trxa), and the intact recombinant visa protein (rvisa) was purified after cleavage with enterokinase t ... | 2002 | 12169606 |
| characterization of virginiamycin s biosynthetic genes from streptomyces virginiae. | streptomyces virginiae produces -butyrolactone autoregulators (virginiae butanolide, vb), which control the biosynthesis of virginiamycin m1 and s. a 6.3-kb region downstream of the virginiamycin s (vs)-resistance operon in s. virginiae was sequenced, and four plausible open reading frames (orfs) (visa, 1,260 bp; visb, 1,656 bp; visc, 888 bp; visd, 1209 bp) were identified. homology analysis revealed significant similarities with enzymes involved in the biosynthesis of cyclopeptolide antibiotics ... | 2002 | 11943483 |
| [isolation of peptide antibiotic virginiamycin components and selection of their producer streptomyces virginiae]. | a method for chromatographic separation and quantitative determination of individual components of the antibiotic virginiamycin, produced by microbiological synthesis (streptomyces virginiae strain 147), is described. the components, m1-2 and s1-5, were isolated from fermentation broth and identified by hptlc and hplc (the results obtained using the two methods correlate well with each other). conditions of culturing of the producer and compositions of nutritive media were optimized. using uv ir ... | 2001 | 11443899 |
| identification of the varr gene as a transcriptional regulator of virginiamycin s resistance in streptomyces virginiae. | a gene designated varr (for virginiae antibiotic resistance regulator) was identified in streptomyces virginiae 89 bp downstream of a vars gene encoding a virginiamycin s (vs)-specific transporter. the deduced varr product showed high homology to repressors of the tetr family with a conserved helix-turn-helix dna binding motif. purified recombinant varr protein was present as a dimer in vitro and showed clear dna binding activity toward the vars promoter region. this binding was abolished by the ... | 2001 | 11222601 |
| identification of an afsa homologue (barx) from streptomyces virginiae as a pleiotropic regulator controlling autoregulator biosynthesis, virginiamycin biosynthesis and virginiamycin m1 resistance. | virginiae butanolide (vb)-bara of streptomyces virginiae is one of the newly discovered pairs of a gamma-butyrolactone autoregulator and the corresponding receptor protein of the streptomyces species, and has been shown to regulate the production of antibiotic virginiamycin (vm) in s. virginiae. a divergently transcribed barx gene is situated 259 bp upstream of the bara gene, and the barx protein has been shown to be highly homologous (39.8% identity, 74. 6% similarity) to s. griseus afsa. altho ... | 2000 | 10792718 |
| characterization of binding sequences for butyrolactone autoregulator receptors in streptomycetes. | bara of streptomyces virginiae is a specific receptor protein for a member of butyrolactone autoregulators which binds to an upstream region of target genes to control transcription, leading to the production of the antibiotic virginiamycin m(1) and s. bara-binding dna sequences (bara-responsive elements [bares]), to which bara binds for transcriptional control, were restricted to 26 to 29-nucleotide (nt) sequences on bara and barb upstream regions by the surface plasmon resonance technique, gel ... | 1999 | 10438781 |
| optimization of agitation and aeration conditions for maximum virginiamycin production. | to maximize the productivity of virginiamycin, which is a commercially important antibiotic as an animal feed additive, an empirical approach was employed in the batch culture of streptomyces virginiae. here, the effects of dissolved oxygen (do) concentration and agitation speed on the maximum cell concentration at the production phase, as well as on the productivity of virginiamycin, were investigated. to maintain the do concentration in the fermentor at a certain level, either the agitation sp ... | 1999 | 10091321 |
| purification and characterization of virginiamycin m1 reductase from streptomyces virginiae. | virginiamycin m1 (vm1), produced by streptomyces virginiae, is a polyunsaturated macrocyclic lactone antibiotic belonging to the virginiamycin a group. s. virginiae possesses an activity which stereospecifically reduces a 16-carbonyl group of vm1, resulting in antibiotically inactive 16r-dihydrovm1. the corresponding vm1 reductase was purified to homogeneity from crude extracts of s. virginiae in five steps, with 5,650-fold purification and 23% overall yield. the n-terminal amino acid sequence w ... | 1998 | 9797237 |
| comparative ribosomal protein (l11 and l30) sequence analyses of several streptomyces spp. commonly used in genetic studies. | the taxonomic relationships among nine strains of streptomyces, which have been commonly used for genetic studies, were examined by sequence analysis of their ribosomal l11(= rplk) protein genes. phylogenetic relationships among these organisms derived from similarity sequence analysis of the rplk genes were in good agreement with those derived from the analysis of the deduced l11 protein amino acid sequence itself, indicating complete sequence homology among streptomyces coelicolor a3(2), 'stre ... | 1998 | 9731302 |
| gene replacement analysis of the streptomyces virginiae bara gene encoding the butyrolactone autoregulator receptor reveals that bara acts as a repressor in virginiamycin biosynthesis. | virginiae butanolides (vbs), which are among the butyrolactone autoregulators of streptomyces species, act as a primary signal in streptomyces virginiae to trigger virginiamycin biosynthesis and possess a specific binding protein, bara. to clarify the in vivo function of bara in the vb-mediated signal pathway that leads to virginiamycin biosynthesis, two bara mutant strains (strains nh1 and nh2) were created by homologous recombination. in strain nh1, an internal 99-bp ecot14i fragment of bara w ... | 1998 | 9642182 |
| purification and characterization of an epsilon-poly-l-lysine-degrading enzyme from an epsilon-poly-l-lysine-producing strain of streptomyces albulus. | an epsilon-poly-l-lysine-degrading enzyme of an epsilon-poly-l-lysine-producing strain of streptomyces albulus was purified and characterized. the enzyme was tightly bound to the cell membrane. after solubilization with nascn, the enzyme was purified to homogeneity by phenyl-sepharose cl-4b column chromatography. the subunit molecular mass of the purified enzyme was 54 kda. enzyme activity was inhibited by o-phenanthroline, and could be restored in the presence of 1 mm mg(2+), ca(2+), fe(3+) or ... | 2002 | 12375099 |
| identification by gene deletion analysis of barb as a negative regulator controlling an early process of virginiamycin biosynthesis in streptomyces virginiae. | the streptomyces virginiae gamma-butyrolactone autoregulator virginiae butanolide is a low-molecular-weight streptomyces hormone eliciting virginiamycin biosynthesis through its binding to the specific receptor protein, bara. immediately downstream of bara lies barb, the transcription of which is tightly repressed by bara in the absence of virginiae butanolide and derepressed in its presence. thus, barb is next to bara on the virginiae butanolide-bara signaling cascade. an in-frame 279-bp deleti ... | 2004 | 14647980 |
| data preprocessing and output evaluation of an autoassociative neural network model for online fault detection in virginiamycin production. | in this study, an artificial autoassociative neural network (aann) was used online to detect deviations from normal antibiotic production fermentation using conventional process variables. to improve the efficiency of extracting hidden information contained in multidimensional process variables, and to finally render the aann adequate for fault detection, we explored the following methods: selection of process variables; preprocessing of data that involved normalizing the training data of the aa ... | 2002 | 16233272 |
| streptomyces-derived induction system for gene expression in cultured plant cells. | we have constructed an induction system for plant gene expression using an operator/repressor gene pair of streptomyces virginiae. in this system, the repressor protein bara dissociates from the operator sequence bare in the presence of an inducer virginiae butanolide (vb), resulting in the induction of the transcription of the operator's downstream genes required for virginiamycin biosynthesis [kinoshita et al., j. bacteriol., 179, 6986-6993 ((1997))]. two vectors were constructed: one was an e ... | 2006 | 17270721 |
| characterization of biosynthetic gene cluster for the production of virginiamycin m, a streptogramin type a antibiotic, in streptomyces virginiae. | virginiamycin m (vm) of streptomyces virginiae is a hybrid polyketide-peptide antibiotic with peptide antibiotic virginiamycin s (vs) as its synergistic counterpart. vm and vs belong to the streptogramin family, which is characterized by strong synergistic antibacterial activity, and their water-soluble derivatives are a new therapeutic option for combating vancomycin-resistant gram-positive bacteria. here, the vm biosynthetic gene cluster was isolated from s. virginiae in the 62-kb region locat ... | 2007 | 17350183 |
| identification by gene deletion analysis of bars2, a gene involved in the biosynthesis of gamma-butyrolactone autoregulator in streptomyces virginiae. | virginiae butanolide (vb) is a member of the gamma-butyrolactone autoregulators and triggers the production of streptogramin antibiotics virginiamycin m1 and s in streptomyces virginiae. a vb biosynthetic gene (bars2) was localized in a 10-kb regulatory island which controls the virginiamycin biosynthesis/resistance of s. virginiae, and analyzed by gene disruption/complementation. the bars2 gene is flanked by bars1, another vb biosynthetic gene catalyzing stereospecific reduction of an a-factor- ... | 2008 | 18034227 |
| maximum virginiamycin production by optimization of cultivation conditions in batch culture with autoregulator addition. | a strategy for optimization of non-growth-associated production in batch culture employing an empirical approach was developed through the study of virginiamycin production. the strategy is formulated with two aims: attaining a high cell concentration at the beginning of the production phase without decrease in production activity; and enhancing the production activity during the production phase. as a practical example, the goal of a maximum virginiamycin (m and s) production in the batch cultu ... | 1996 | 18623599 |
| hierarchical control of virginiamycin production in streptomyces virginiae by three pathway-specific regulators: vmss, vmst and vmsr. | two regulatory genes encoding a streptomyces antibiotic regulatory protein (vmss) and a response regulator (vmst) of a bacterial two-component signal transduction system are present in the left-hand region of the biosynthetic gene cluster of the antibiotic virginiamycin, which is composed of virginiamycin m (vm) and virginiamycin s (vs), in streptomyces virginiae. disruption of vmss abolished both vm and vs biosynthesis, with drastic alteration of the transcriptional profile for virginiamycin bi ... | 2009 | 19332826 |
| cholesterol oxidase chol is a critical enzyme that catalyzes the conversion of diosgenin to 4-ene-3-keto steroids in streptomyces virginiae ibl-14. | diosgenin transformation was studied in streptomyces virginiae ibl-14, a soil-dwelling bacterium with diosgenin-degrading capacity. all of the derivatives isolated were identified as 4-ene-3-keto steroids. we cloned chol, a fragment of a cholesterol oxidase from s. virginiae ibl-14, and used gene-disruption techniques to determine its function in the oxidation of diosgenin to 4-ene-3-keto steroids. subsequently, the entire open reading frame of chol was cloned by chromosome walking, and the his( ... | 2010 | 19711070 |
| new microbiological transformations of steroids by streptomyces virginiae ibl-14. | a bacterium streptomyces virginiae ibl-14 capable of effective degradation of diosgenin was isolated from activated sludge for treatment of waste from a steroidal drug factory. from the culture broth of diosgenin degradation, 11 compounds were purified and then identified, eight of which were previously unidentified compounds including 1-dehydroisonuatigenone [vi], nuatigenone [viii], 1-dehydronuatigenone [x], 26-acetyl-nuatigenone [xii], 6-methoxy-6-dehydrodiosgenone [xiii], 6-methoxy-6-dehydro ... | 2009 | 19731705 |
| null mutation analysis of an afsa-family gene, barx, that is involved in biosynthesis of the {gamma}-butyrolactone autoregulator in streptomyces virginiae. | virginiae butanolide (vb) is a gamma-butyrolactone autoregulator that triggers production of the streptogramin antibiotic virginiamycin in streptomyces virginiae. our previous studies suggested that the barx gene, an afsa-family gene, is likely to participate in the regulatory pathway for the production of vb, rather than in the biosynthetic pathway of vb itself, in contrast to the function of other afsa-family genes. mutation analysis now shows that barx at least plays an enzymic role in the vb ... | 2010 | 19778967 |
| visg is essential for biosynthesis of virginiamycin s, a streptogramin type b antibiotic, as a provider of the nonproteinogenic amino acid phenylglycine. | a streptogramin type b antibiotic, virginiamycin s (vs), is produced by streptomyces virginiae, together with a streptogramin type a antibiotic, virginiamycin m1 (vm), as its synergistic counterpart. vs is a cyclic hexadepsipeptide containing a nonproteinogenic amino acid, l-phenylglycine (phegly), in its core structure. we have identified, in the left-hand extremity of the virginiamycin supercluster, two genes that direct vs biosynthesis with phegly incorporation. transcriptional analysis revea ... | 2011 | 21816878 |
| identification and functional analysis of cytochrome p450 complement in streptomyces virginiae ibl14. | as well known, both natural and synthetic steroidal compounds are powerful endocrine disrupting compounds (edcs) which can cause reproductive toxicity and affect cellular development in mammals and thus are generally regarded as serious contributors to water pollution. streptomyces virginiae ibl14 is an effective degradative strain for many steroidal compounds and can also catalyze the c25 hydroxylation of diosgenin, the first-ever biotransformation found on the f-ring of diosgenin. | 2013 | 23442312 |
| [physico-chemical properties and structure of oligomycin sc-ii, produced by streptomyces virginiae 17]. | under the screening programme for antibiotics with antifungal and immunosuppressive activities, streptomyces virginiae 17 producing an oligomycin complex was isolated. separation of the complex by hplc showed that it contained two components at a ratio of 8:2. the physico-chemical characteristics of the components were investigated. the structure of oligomycin was assessed by 13c nmr and 1h nmr. | 2012 | 23700929 |
| streptomyces manipurensis sp. nov., a novel actinomycete isolated from a limestone deposit site in manipur, india. | a novel actinobacterium, designated mbrl 201(t), was isolated from a sample collected from a limestone quarry at hundung, manipur, india. the strain was characterized using polyphasic taxonomy. comparison of the 16s rrna gene sequence of strain mbrl 201(t) and other streptomyces species showed sequence similarities ranging from 93.0 to 99.6 % and strain mbrl 201(t) showed closest similarities to streptomyces virginiae nbrc 12827(t) (99.6 %) and streptomyces cinnamonensis nbrc 15873(t) (99.6 %). ... | 2012 | 22421918 |
| scaling up a virginiamycin production by a high-yield streptomyces virginiae vkm ac-2738d strain using adsorbing resin addition and fed-batch fermentation under controlled conditions. | virginiamycin produced by streptomyces virginiae as a natural mix of macrocyclic peptidolactones m and s is widely used in the industrial production of ethanol fuel and as an antibiotic feed additive for cattle and poultry. its main antimicrobial components, m1 and s1 factors, act synergistically if the m1:s1 ratio in the final product is 70-75:25-30. this fact significantly complicates the development of stable high-yield strains suitable for industrial application. in the previous work, author ... | 2016 | 28330311 |
| studies on the function and catalytic mechanism of o-methyltransferases sviomt02, sviomt03 and sviomt06 from streptomyces virginiae ibl14. | to identify the fuctions of the nine putative o-methyltransferase genes in streptomyces virginiae ibl14, the evolutionary and functional relationship of these genes in its 8.0 mb linear chromosome was set up via sequence comparison with those of other streptomyces species. further, the functions and catalytic mechanism of the three genes sviomt02, sviomt03 and sviomt06 from this strain were studied through experimental and computational approaches. as a result, the nine putative o-methyltransfer ... | 2015 | 26002507 |