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PubMed1996

Isolation and characterization of a gene from Streptomyces sp. strain C5 that confers the ability to convert daunomycin to doxorubicin on Streptomyces lividans TK24.

DNA sequence analysis of a region of the Streptomyces sp. strain C5 daunomycin biosynthesis gene cluster, located between the daunomycin polyketide biosynthesis gene cluster and a dnrI (transcriptional activator) homolog, revealed the presence of a gene encoding a P-450-like enzyme with a deduced Mr of 46,096. Expression of this gene, named herein doxA, in Streptomyces lividans TY24 resulted in in vivo bioconversion of daunomycin to doxorubicin. DoxA showed specificity for only daunomycin and 13-dihydrodaunomycin, both of which were converted to doxorubicin. Daunomycinone (daunomycin aglycone), carminomycin, 13-dihydrocarminomycin, idarubicin, and aklavin were not apparent substrates for DoxA. In vector controls or in vectors in which doxA was poorly expressed, S. lividans catalyzed the reduction of daunomycin and other 13-oxo-anthracyclines and -anthracyclinones to their 13-dihydro homologs.

Amino Acid Sequence↗
PubMed2005

Involvement of AlpV, a new member of the Streptomyces antibiotic regulatory protein family, in regulation of the duplicated type II polyketide synthase alp gene cluster in Streptomyces ambofaciens.

A type II polyketide synthase gene cluster located in the terminal inverted repeats of Streptomyces ambofaciens ATCC 23877 was shown to be responsible for the production of an orange pigment and alpomycin, a new antibiotic probably belonging to the angucycline/angucyclinone class. Remarkably, this alp cluster contains five potential regulatory genes, three of which (alpT, alpU, and alpV) encode proteins with high similarity to members of the Streptomyces antibiotic regulatory protein (SARP) family. Deletion of the two copies of alpV (one in each alp cluster located at the two termini) abolished pigment and antibiotic production, suggesting that AlpV acts as a transcriptional activator of the biosynthetic genes. Consistent with this idea, the transcription of alpA, which encodes a ketosynthase essential for orange pigment and antibiotic production, was impaired in the alpV mutant, while the expression of alpT, alpU, and alpZ, another regulatory gene encoding a gamma-butyrolactone receptor, was not significantly affected. Real-time PCR experiments showed that transcription of alpV in the wild-type strain increases dramatically after entering the transition phase. This induction precedes that of alpA, suggesting that AlpV needs to reach a threshold level to activate the expression of the structural genes. When introduced into an S. coelicolor mutant with deletions of actII-ORF4 and redD, the SARP-encoding genes regulating the biosynthesis of actinorhodin and undecylprodigiosin, respectively, alpV was able to restore actinorhodin production only. However, actII-ORF4 did not complement the alpV mutant, suggesting that AlpV and ActII-ORF4 may act in a different way.

Amino Acid Sequence↗
PubMed1979

The 2.8 A resolution structure of Streptomyces griseus protease B and its homology with alpha-chymotrypsin and Streptomyces griseus protease A.

The 2.8 A (1 A = 0.1 nm) resolution structure of the crystalline orthorhombic form of the microbial serine protease Streptomyces griseus protease B (SGPB) has been solved by the method of multiple isomorphous replacement using five heavy-atom derivatives. The geometrical arrangement of the active site quartet, Ser-214, Asp-102, His-57, and Ser-195, is similar to that found for pancreatic alpha-chymotrypsin. SGPB and alpha-chymotrypsin have only 18% identity of primary structure but their tertiary structures are 63% topologically equivalent within a root mean square deviation of 2.07 A. The major tertiary structural differences between the bacterial enzyme SGPB and the pancreatic enzymes is due to the zymogen requirement of the multicellular organisms in order to protect themselves against autolytic degradation. The two pronase enzymes, SGPB and Streptomyces griseus protease A (SGPA), have 61% identity of sequence and their tertiary structures are 85% topologically equivalent within a root mean square deviation of 1.46 A. The active site regions of SGPA and SGPB are similar and their tertiary structures differ only in three minor regions of surface loops.

Amino Acid Sequence↗
PubMed2005

Cloning and sequencing of an exoglucanase gene from Streptomyces sp. M 23, and its expression in Streptomyces lividans TK-24.

A gene encoding exoglucanase (CBHII) of Streptomyces sp. M 23 was cloned and sequenced. The cbhII gene consisted of 1359 bp capable of encoding a polypeptide of 453 amino acids with a calculated molecular mass of 45,175 Da. The deduced amino acid sequence showed homology with those of cellulases belonging to family 6 of the glycosyl hydrolases. The cbhII gene was subcloned into the plasmid pSEV1 and expressed in Streptomyces lividans TK-24. The transformed cells were able to secrete the enzyme efficiently in an active form. The CBHII expressed by S. lividans TK-24 was purified to homogeneity by SDS-polyacrylamide gel and characterized. The recombinant CBHII was stable up to 50 degrees C and more than 30% of the original activity remained after heating at 100 degrees C for 10 min. The amino-terminal amino acid sequence of the recombinant CBHII was identified as GPAAPTARVD. These results agreed well with the properties of the authentic CBHII.

Amino Acid Sequence↗
PubMed1993

Studies on cell growth stimulating substances of low molecular weight. Part 2. Exfoliazone and lavanducyanin, potent growth promoting substances of rat liver cell line, RLN-8, produced by Streptomyces exfoliatus and Streptomyces aeriouvifer.

Exfoliazone and lavanducyanin isolated from Streptomyces exfoliatus BT-38 and Streptomyces aeriouvifer CL-190, respectively, showed strong growth promoting activities to liver cell RLN-8 established from normal Donryu rat. When RLN-8 cells were cultured in Eagle's minimal essential medium containing 1% fetal bovine serum, exfoliazone significantly stimulated the growth of RLN-8 cells. However, no effect was observed under serum-free conditions. Effective dose of exfoliazone was at the range of 0.004-0.1 microgram/ml. Cell proliferation was confirmed by MTT assay and by the increases of cell number and DNA synthesis. Lavanducyanin also stimulated the growth of RLN-8 cells in the same medium. It showed growth promoting activity at lower concentrations than exfoliazone and the effective dose was at the range of 0.0001-0.06 microgram/ml. Analogous compounds of exfoliazone and lavanducyanin also promoted the growth of RLN-8 cells. In addition, exfoliazone and lavanducyanin enhanced the growth of NIH 3T3 and T601 cells. These results indicate that exfoliazone, lavanducyanin and their related compounds seem to be a new type of growth promoting substances with low molecular weight produced by microorganisms, and that they can partially substitute for functions of serum. Since 12-O-tetradecanoylphorbol-13-acetate (TPA) did not show the growth promoting activities under the same conditions, the action mechanism(s) of exfoliazone and lavanducyanin are different from that of TPA.

Animals↗
PubMed2000

Application of redD, the transcriptional activator gene of the undecylprodigiosin biosynthetic pathway, as a reporter for transcriptional activity in Streptomyces coelicolor A3(2) and Streptomyces lividans.

redD encodes the transcriptional activator of the biosynthetic pathway for undecylprodigiosin, a red-pigmented, mycelium-bound antibiotic made by Streptomyces coelicolor A3(2) and Streptomyces lividans. A promoterless version of redD preceded by the efficiently used tuf1 ribosome binding site was inserted into two different plasmid vectors, providing a convenient reporter of transcriptional activity in both species. One plasmid, plJ2587, replicates autonomously in both Escherichia coli and streptomycetes, while the other, plJ2585, replicates in E. coli and can be transferred to streptomycetes by conjugation or transformation, whereupon it integrates stably at the chromosomal attachment site for the temperate phage phiC31. The utility of the plasmids in detecting not only transcriptional activity, but also its regulation, was confirmed using the rrnAp, ermEp*, and glnRp promoters. The ability to screen visually and spectrophotometrically for red pigmentation should make the vectors particularly attractive for analysing the regulation of gene expression, and for the isolation of mutants, in both S. coelicolor and S. lividans.

Amino Acid Sequence↗
PubMedDate not supplied

[Effect of cloned DNA fragment from Streptomyces chrysomallus No.2 on metabolism in Streptomyces strains].

The effects on cloned DNA fragment carrying an actinomycin resistance determinant on physiological processes in streptomyces strains with various potencies in producing this antibiotic, their inactive mutants, and model strain of Streptomyces lividans 66 were studied. This fragment was shown to modulate bacterial resistance to actinomycin and biosynthesis of antibiotics.

Cloning, Molecular↗
PubMedDate not supplied

[Purification and physico-chemical properties of Streptomyces sp. 1349 collagenase and Streptomyces sp. 1382 keratinase].

The schemes of isolation and purification of collagenolytic enzymes of Streptomyces sp. 1349 and keratinolyte enzymes of Streptomyces sp. 1382, which include fractionation by ammonium sulphate separation on TSK-gels: ion-exchange chromatography on Toyopearl DEAE-650(M) and gel-filtration on Toyopearl HW-50, as well as highly efficient liquid chromatography. The purified enzyme preparations proved to be proteases of serine type (collagenase 2 and keratinases) as well as metalloproteases (collagenases 1 and 3). It has seen established that collagenases are enzymes of broad specificity, which are active in respect of proteins of both globular and fibrillar nature. And vice versa, keratinases are proteolytic enzymes of narrow specificity which hydrolyze native keratin. Molecular masses of purified enzyme preparations, from the data of SDS-PAAG are approximately 30-40 kDa (collagenases 1-3) and about 15-20 kDa (keratinases 1 and 2). It is shown that the charged aminoacid residues (about 85%) prevail in enzyme molecules. The enzymes are distinguished by pH- and thermooptima.

Ammonium Sulfate↗
PubMedDate not supplied

[Substrate specificity of collagenase of Streptomyces sp. 1349 and keratinase of Streptomyces sp. 1382].

The paper determines the action specificity concerning the bonding type of collagenases of Strepomyces sp. 1349 and keratinases of Streptomyces sp. 1382. Experimental data obtained evidence for the wide specificity of the obtained enzymatic drugs. It has been established that both collagenases and keratinases display high specificity in respect of the bonds made by the residues of hydrophobic amino acids. Collagenases of Streptomyces sp. 1349, as to their wide action specificity, differed from collagenase of Clostridium histolyticum described in literature, that was confirmed by the results of double immunodiffusion in agar by Ouchterloni. Preparations of streptomycete collagenase obtained by the authors did not interact with serum obtained for highly purified collagenase of C. histolyticum of the firm "Merck". Investigation of the feather keratin lysates by the fractions of keratinases 1 and 2 have shown the difference in the content of amino acids released after hydrolysis that may be determined by different specificity of the enzymes action. Cysteine in the amount of 3.8% was also found in keratin lysate of the enzymatic fraction 1, that may evidence for the capacity of the fraction 1 to break the disulphide bonds in keratin molecule.

Amino Acids↗
PubMed1989

Interspecific protoplast fusion of Streptomyces hygroscopicus var. yingchengenisis with Streptomyces qingfengmyceticus and biological characterization of their recombinants.

The frequency of recombination between Streptomyces hygroscopicus var. yingchengensis and Streptomyces qingfengmyceticus as a result of interspecific protoplast fusion was 4.5 x 10(-4). Characterization of biological properties revealed differences in spore mass color, drug resistance, antimicrobial activity, and antibiotic production capacity between the recombinants and their parents. Two recombinant strains, FL-42 and FL-48, exhibited production of the antibiotics originally elaborated by the two parents individually. They also produced two compounds with antimicrobial activity that their parents could not synthesize.

Anti-Bacterial Agents↗
PubMed1985

[Metabolism of phosphate-limited Streptomyces cultures. III. The ambivalent effect of phosphates in nourseothricin-producing cultures of Streptomyces noursei JA 3890b].

A common condition in the evolution of organisms and their metabolism seems to be a latent lack of available phosphate in the natural environment. Accordingly, the phosphate dependent metabolisms of the soil-living streptomycetes should be stamped by lack of phosphate, too. The biosynthesis of the streptothricin antibiotic nourseothricin by Streptomyces noursei 3890b is initiated by limitation of soluble phosphate in the fermentation medium. At the other side is shown that a certain rate of feeding of phosphate during the fermentation increases the nourseothricin biosynthesis. An ambivalente role of phosphate on the secondary metabolite biosynthesis is stated. The limitation of phosphate leads to a special physiological state of the producer, characterized by secondary product formation and dephosphorylating activities in cells. This state is temporally stabilized by the presence of a sufficient phosphate supply, realized by enzymatic hydrolysis of complex phosphate-containing substrates or by a direct feeding of inorganic phosphate to the fermentations. The occurrence of different physiological states in respect to the phosphate-dependent metabolism is described by S-shaped functions of the relationship between specific growth rate and the phosphate concentration in the medium. The special behaviour of Streptomyces noursei cells at phosphate limitation is discussed to be the result of the dephosphorylating activities in cells, hydrolyzing phosphoester-bonds of regulatory metabolites as well as energy-rich compounds.

Anti-Bacterial Agents↗
PubMed1994

Triple hydroxylation of tetracenomycin A2 to tetracenomycin C in Streptomyces glaucescens. Overexpression of the tcmG gene in Streptomyces lividans and characterization of the tetracenomycin A2 oxygenase.

Nucleotide sequence analysis of the tcmG gene has suggested that the TcmG protein is responsible for the triple-hydroxylation of tetracenomycin (Tcm) A2 to Tcm C in Streptomyces glaucescens (Decker, H., Motamedi, H., and Hutchinson, C.R. (1993) J. Bacteriol. 175, 3876-3886). The heterologous expression of the tcmG gene in Streptomyces lividans and the purification and characterization of TcmG protein, which we have named Tcm A2 oxygenase, are described here. NH2-terminal amino acid analysis of the purified enzyme led to the revision of the translational start site of tcmG to a TTG, 33 base pairs downstream of the GTG site assigned initially on the basis of nucleotide sequence analysis. Tcm A2 oxygenase is a monomeric protein in solution and contains 1 mol of non-covalently bound FAD; the apoenzyme can be partially reconstituted in vitro by addition of FAD. Tcm A2 oxygenase exhibits an optimal pH of 9.0-9.5 and prefers NADPH over NADH as an electron donor. The apparent K'm of the enzyme for Tcm A2, NADH, and NADPH are 1.81 +/- 0.38, 260 +/- 19, and 82.1 +/- 17 microM, respectively, and the apparent V'max for the reaction is 14.7 +/- 1.1 nmol Tcm C/min.mg. Purification and characterization of Tcm A2 oxygenase provide direct evidence to support the notion that the angular hydroxy groups of naphthacenequinones like Tcm C are introduced from 18O2 via a mono- or dioxygenase process.

Amino Acid Sequence↗
PubMed1998

[Novel L-glutamate oxidase producing organisms: Streptomyces litmocidini and Streptomyces cremeus].

Two novel strains i.e. Streptomyces cremeus 510 and Streptomyces litmocidini 447 producing L-glutamate oxidase were isolated from soil samples and identified. Mathematical design of the experiments made it possible to optimize the fermentation medium composition which provided at least a 5-fold increase of the strain L-glutamate oxidase activity by comparison with the initial activity in the standard medium.

Amino Acid Oxidoreductases↗
PubMed2004

High level expression of Streptomyces mobaraensis transglutaminase in Corynebacterium glutamicum using a chimeric pro-region from Streptomyces cinnamoneus transglutaminase.

We previously observed secretion of native-type Streptomyces mobaraensis transglutaminase (MTGase) in Corynebacterium glutamicum by co-expressing the subtilisin-like protease SAM-P45 from S. albogriseolus which processes the pro-region. In the present study, we have used a chimeric pro-region consisting of S. mobaraensis and Streptomyces cinnamoneus transglutaminases for the production of MTGase in C. glutamicum. As a result, secretion of MTGase using the chimeric pro-region is increased compared to that using the native pro-region.

Amino Acid Sequence↗
PubMed1992

Expression of Streptomyces genes encoding extracellular enzymes in Brevibacterium lactofermentum: secretion proceeds by removal of the same leader peptide as in Streptomyces lividans.

The alpha-amylase gene (amy) from Streptomyces griseus IMRU 3570 and the beta-galactosidase gene (lac) from S. lividans were subcloned into Brevibacterium lactofermentum or B. lactofermentum/Escherichia coli shuttle vectors. The amy gene was not expressed in B. lactofermentum from its own promoter but was efficiently expressed when the promoter of the kanamycin resistance gene (kan) was inserted upstream of the promoterless amylase gene. The lac gene from S. lividans was subcloned without its native promoter and was expressed when placed downstream of pBL1 promoters P2 or P3. The alpha-amylase was secreted extracellularly by removal of the same 28-amino acid leader peptide as in S. lividans. The amy and lac genes provide useful markers for selection of transformants and will facilitate the study of protein secretion in B. lactofermentum.

Amino Acid Sequence↗
PubMed1991

Effects of replacement of promoters and modification of the leader peptide region of the amy gene of Streptomyces griseus on synthesis and secretion of alpha-amylase by Streptomyces lividans.

Five different mutations were introduced into the leader peptide region of the alpha-amylase gene of Streptomyces griseus IMRU 3570. A mutation which increased the positive charge of the N-terminal region of the leader peptide enhanced the secretion of alpha-amylase by two- to threefold. Replacement of the native promoter of the amylase gene by the promoter of the Tn5 neo gene or by the promoter of the saf gene resulted in a 16-fold increase in alpha-amylase secretion. The enhanced secretion of alpha-amylase obtained by using the most efficient promoters was due to a correlated increase in the amount of transcript formed. The translation and secretion processes in S. lividans are not a bottleneck for enzyme secretion even at very high transcription rates, since stimulation of transcription of the alpha-amylase gene results in a proportionate increase in secretion of the enzyme.

Amino Acid Sequence↗
PubMed1983

Cloning and expression of the tyrosinase gene from Streptomyces antibioticus in Streptomyces lividans.

In two separate studies a BclI-generated DNA fragment coding for the enzyme tyrosinase, responsible for melanin synthesis, was cloned from Streptomyces antibioticus DNA into two SLP1.2-based plasmid vectors (pIJ37 and pIJ41) to generate the hybrid plasmids, designated pIJ700 and pIJ701, using S. lividans 66 as the host. The fragment (1.55 kb) was subcloned into the multicopy plasmid pIJ350 (which carries thiostrepton resistance and has two non-essential BclI sites) to generate four new plasmids (pIJ702-pIJ705) with the tyrosinase insert located in either orientation at each site. All six plasmids conferred melanin production (the Mel+ phenotype) on their host. As in the S. antibioticus parent, strains of S. lividans carrying the gene specifying tyrosinase synthesis possessed an enzyme activity which was inducible. Most of the tyrosinase activity was secreted during growth of S. antibioticus; in contrast, the majority remained intracellular in the S. lividans clones. The specific activity of the induced tyrosinase activity (intracellular) was higher (up to 36-fold) when the gene was present on the multicopy vector in comparison with its location on the low copy plasmids, pIJ700 or pIJ701, or in S. antibioticus. Restriction mapping of the tyrosinase fragment in pIJ702 revealed endonuclease cleavage sites for several enzymes, including single sites for BglII, SphI and SstI that are absent from the parent vector (pIJ350). Insertion of DNA fragments at any one of these sites abolished the Mel+ phenotype. The results indicate that pIJ702 is a useful cloning vector with insertional inactivation of the Mel+ character as the basis of clone recognition.

Catechol Oxidase↗