scholarly journals The Product of a Developmental Gene, crgA, That Coordinates Reproductive Growth in Streptomyces Belongs to a Novel Family of Small Actinomycete-Specific Proteins

2003 ◽  
Vol 185 (22) ◽  
pp. 6678-6685 ◽  
Author(s):  
Ricardo Del Sol ◽  
Andrew Pitman ◽  
Paul Herron ◽  
Paul Dyson
Keyword(s):  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Orthologous Gene ◽  
Streptomyces Avermitilis ◽  
Antibiotic Biosynthesis ◽  
Reproductive Growth ◽  
Solid Media ◽  
Aerial Hyphae ◽  
A Chain ◽  
Membrane Spanning

ABSTRACT On solid media, the reproductive growth of Streptomyces involves antibiotic biosynthesis coincident with the erection of filamentous aerial hyphae. Following cessation of growth of an aerial hypha, multiple septation occurs at the tip to form a chain of unigenomic spores. A gene, crgA, that coordinates several aspects of this reproductive growth is described. The gene product is representative of a well-conserved family of small actinomycete proteins with two C-terminal hydrophobic-potential membrane-spanning segments. In Streptomyces avermitilis, crgA is required for sporulation, and inactivation of the gene abolished most sporulation septation in aerial hyphae. Disruption of the orthologous gene in Streptomyces coelicolor indicates that whereas CrgA is not essential for sporulation in this species, during growth on glucose-containing media, it influences the timing of the onset of reproductive growth, with precocious erection of aerial hyphae and antibiotic production by the mutant. Moreover, CrgA subsequently acts to inhibit sporulation septation prior to growth arrest of aerial hyphae. Overexpression of CrgA in S. coelicolor, uncoupling any nutritional and growth phase-dependent regulation, results in growth of nonseptated aerial hyphae on all media tested, consistent with a role for the protein in inhibiting sporulation septation.

scholarly journals The RNA Polymerase Omega Factor RpoZ Is Regulated by PhoP and Has an Important Role in Antibiotic Biosynthesis and Morphological Differentiation in Streptomyces coelicolor

2011 ◽  
Vol 77 (21) ◽  
pp. 7586-7594 ◽  
Author(s):  
Fernando Santos-Beneit ◽  
Mónica Barriuso-Iglesias ◽  
Lorena T. Fernández-Martínez ◽  
Miriam Martínez-Castro ◽  
Alberto Sola-Landa ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Response Regulator ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Luciferase Reporter ◽  
Antibiotic Biosynthesis ◽  
Binding Assays ◽  
Content Type ◽  
Phosphate Depletion

ABSTRACTThe RNA polymerase (RNAP) omega factor (ω) forms a complex with the α2ββ′ core of this enzyme in bacteria. We have characterized therpoZgene ofStreptomyces coelicolor, which encodes a small protein (90 amino acids) identified as the omega factor. Deletion of therpoZgene resulted in strains with a slightly reduced growth rate, although they were still able to sporulate. The biosynthesis of actinorhodin and, particularly, that of undecylprodigiosin were drastically reduced in the ΔrpoZstrain, suggesting that expression of these secondary metabolite biosynthetic genes is dependent upon the presence of RpoZ in the RNAP complex. Complementation of the ΔrpoZmutant with the wild-typerpoZallele restored both phenotype and antibiotic production. Interestingly, therpoZgene contains a PHO box in its promoter region. DNA binding assays showed that the phosphate response regulator PhoP binds to such a region. Since luciferase reporter studies showed thatrpoZpromoter activity was increased in a ΔphoPbackground, it can be concluded thatrpoZis controlled negatively by PhoP, thus connecting phosphate depletion regulation with antibiotic production and morphological differentiation inStreptomyces.

Predicted highly expressed genes in the genomes of Streptomyces coelicolor and Streptomyces avermitilis and the implications for their metabolism

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2175-2187 ◽  
Author(s):  
Gang Wu ◽  
David E. Culley ◽  
Weiwen Zhang
Keyword(s):  
Polyketide Synthase ◽  
Streptomyces Coelicolor ◽  
Orthologous Gene ◽  
Housekeeping Genes ◽  
Streptomyces Avermitilis ◽  
Ribosomal Protein Genes ◽  
Polyketide Synthase Gene ◽  
Highly Expressed Genes ◽  
Adenosylmethionine Synthetase ◽  
Coa Reductase

Highly expressed genes in bacteria often have a stronger codon bias than genes expressed at lower levels, due to translational selection. In this study, a comparative analysis of predicted highly expressed (PHX) genes in the Streptomyces coelicolor and Streptomyces avermitilis genomes was performed using the codon adaptation index (CAI) as a numerical estimator of gene expression level. Although it has been suggested that there is little heterogeneity in codon usage in G+C-rich bacteria, considerable heterogeneity was found among genes in these two G+C-rich Streptomyces genomes. Using ribosomal protein genes as references, ∼10 % of the genes were predicted to be PHX genes using a CAI cutoff value of greater than 0·78 and 0·75 in S. coelicolor and S. avermitilis, respectively. The PHX genes showed good agreement with the experimental data on expression levels obtained from proteomic analysis by previous workers. Among 724 and 730 PHX genes identified from S. coelicolor and S. avermitilis, 368 are orthologue genes present in both genomes, which were mostly ‘housekeeping’ genes involved in cell growth. In addition, 61 orthologous gene pairs with unknown functions were identified as PHX. Only one polyketide synthase gene from each Streptomyces genome was predicted as PHX. Nevertheless, several key genes responsible for producing precursors for secondary metabolites, such as crotonyl-CoA reductase and propionyl-CoA carboxylase, and genes necessary for initiation of secondary metabolism, such as adenosylmethionine synthetase, were among the PHX genes in the two Streptomyces species. The PHX genes exclusive to each genome, and what they imply regarding cellular metabolism, are also discussed.

scholarly journals Influence of CrgA on Assembly of the Cell Division Protein FtsZ during Development of Streptomyces coelicolor

2006 ◽  
Vol 188 (4) ◽  
pp. 1540-1550 ◽  
Author(s):  
Ricardo Del Sol ◽  
Jonathan G. L. Mullins ◽  
Nina Grantcharova ◽  
Klas Flärdh ◽  
Paul Dyson
Keyword(s):  
Cell Division ◽  
Streptomyces Coelicolor ◽  
Orthologous Gene ◽  
Integral Membrane Protein ◽  
Origin Of Replication ◽  
Small Proteins ◽  
Aerial Hyphae ◽  
Z Ring ◽  
Cell Division Protein ◽  
Conserved Gene

ABSTRACT The product of the crgA gene of Streptomyces coelicolor represents a novel family of small proteins. A single orthologous gene is located close to the origin of replication of all fully sequenced actinomycete genomes and borders a conserved gene cluster implicated in cell growth and division. In S. coelicolor, CrgA is important for coordinating growth and cell division in sporogenic hyphae. In this study, we demonstrate that CrgA is an integral membrane protein whose peak expression is coordinated with the onset of development of aerial hyphae. The protein localizes to discrete foci away from growing hyphal tips. Upon overexpression, CrgA localizes to apical syncytial cells of aerial hyphae and inhibits the formation of productive cytokinetic rings of the bacterial tubulin homolog FtsZ, leading to proteolytic turnover of this major cell division determinant. In the absence of known prokaryotic cell division inhibitors in actinomycetes, CrgA may have an important conserved function influencing Z-ring formation in these bacteria.

scholarly journals Large-Scale Transposition Mutagenesis of Streptomyces coelicolor Identifies Hundreds of Genes Influencing Antibiotic Biosynthesis

2017 ◽  
Vol 83 (6) ◽  
Author(s):  
Zhong Xu ◽  
Yemin Wang ◽  
Keith F. Chater ◽  
Hong-Yu Ou ◽  
H. Howard Xu ◽  
...  
Keyword(s):  
Secondary Metabolism ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Insertion Site ◽  
Strain Improvement ◽  
Target Site ◽  
Antibiotic Biosynthesis ◽  
Biosynthetic Gene ◽  
Gram Positive ◽  
Content Type

ABSTRACT Gram-positive Streptomyces bacteria produce thousands of bioactive secondary metabolites, including antibiotics. To systematically investigate genes affecting secondary metabolism, we developed a hyperactive transposase-based Tn5 transposition system and employed it to mutagenize the model species Streptomyces coelicolor, leading to the identification of 51,443 transposition insertions. These insertions were distributed randomly along the chromosome except for some preferred regions associated with relatively low GC content in the chromosomal core. The base composition of the insertion site and its flanking sequences compiled from the 51,443 insertions implied a 19-bp expanded target site surrounding the insertion site, with a slight nucleic acid base preference in some positions, suggesting a relative randomness of Tn5 transposition targeting in the high-GC Streptomyces genome. From the mutagenesis library, 724 mutants involving 365 genes had altered levels of production of the tripyrrole antibiotic undecylprodigiosin (RED), including 17 genes in the RED biosynthetic gene cluster. Genetic complementation revealed that most of the insertions (more than two-thirds) were responsible for the changed antibiotic production. Genes associated with branched-chain amino acid biosynthesis, DNA metabolism, and protein modification affected RED production, and genes involved in signaling, stress, and transcriptional regulation were overrepresented. Some insertions caused dramatic changes in RED production, identifying future targets for strain improvement. IMPORTANCE High-GC Gram-positive streptomycetes and related actinomycetes have provided more than 100 clinical drugs used as antibiotics, immunosuppressants, and antitumor drugs. Their genomes harbor biosynthetic genes for many more unknown compounds with potential as future drugs. Here we developed a useful genome-wide mutagenesis tool based on the transposon Tn5 for the study of secondary metabolism and its regulation. Using Streptomyces coelicolor as a model strain, we found that chromosomal insertion was relatively random, except at some hot spots, though there was evidence of a slightly preferred 19-bp target site. We then used prodiginine production as a model to systematically survey genes affecting antibiotic biosynthesis, providing a global view of antibiotic regulation. The analysis revealed 348 genes that modulate antibiotic production, among which more than half act to reduce production. These might be valuable targets in future investigations of regulatory mechanisms, for strain improvement, and for the activation of silent biosynthetic gene clusters.

scholarly journals Regulation of a Novel Gene Cluster Involved in Secondary Metabolite Production in Streptomyces coelicolor

2010 ◽  
Vol 192 (19) ◽  
pp. 4973-4982 ◽  
Author(s):  
Hindra ◽  
Patricia Pak ◽  
Marie A. Elliot
Keyword(s):  
Gene Cluster ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Genetic Locus ◽  
Regulatory Protein ◽  
Negative Control ◽  
Antibiotic Biosynthesis ◽  
Rnase Iii ◽  
Protein Encoding ◽  
Actinorhodin Production

ABSTRACT Antibiotic biosynthesis in the streptomycetes is a complex and highly regulated process. Here, we provide evidence for the contribution of a novel genetic locus to antibiotic production in Streptomyces coelicolor. The overexpression of a gene cluster comprising four protein-encoding genes (abeABCD) and an antisense RNA-encoding gene (α-abeA) stimulated the production of the blue-pigmented metabolite actinorhodin on solid medium. Actinorhodin production also was enhanced by the overexpression of an adjacent gene (abeR) encoding a predicted Streptomyces antibiotic regulatory protein (SARP), while the deletion of this gene impaired actinorhodin production. We found the abe genes to be differentially regulated and controlled at multiple levels. Upstream of abeA was a promoter that directed the transcription of abeABCD at a low but constitutive level. The expression of abeBCD was, however, significantly upregulated at a time that coincided with the initiation of aerial development and the onset of secondary metabolism; this expression was activated by the binding of AbeR to four heptameric repeats upstream of a promoter within abeA. Expressed divergently to the abeBCD promoter was α-abeA, whose expression mirrored that of abeBCD but did not require activation by AbeR. Instead, α-abeA transcript levels were subject to negative control by the double-strand-specific RNase, RNase III.

scholarly journals Putative TetR Family Transcriptional Regulator SCO1712 Encodes an Antibiotic Downregulator in Streptomyces coelicolor

2010 ◽  
Vol 76 (9) ◽  
pp. 3039-3043 ◽  
Author(s):  
Han-Na Lee ◽  
Jianqiang Huang ◽  
Jong-Hyuk Im ◽  
Seon-Hye Kim ◽  
Jun-Hee Noh ◽  
...  
Keyword(s):  
Microarray Analysis ◽  
Dna Microarray ◽  
Deletion Mutant ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Regulatory Gene ◽  
Transcriptional Regulator ◽  
Antibiotic Biosynthesis ◽  
Dna Microarray Analysis ◽  
Transcriptional Regulatory

ABSTRACT A tetR family transcriptional regulatory gene (SCO1712) was identified as a global antibiotic regulatory gene from a Streptomyces interspecies DNA microarray analysis. SCO1712 disruption in S treptomyces coelicolor not only upregulated antibiotic biosynthesis through pathway-specific regulators when a previously identified pleiotropic downregulatory wblA was expressed but also further stimulated antibiotic production in a wblA deletion mutant, implying that SCO1712 might encode a novel antibiotic downregulator.

scholarly journals Interspecies DNA Microarray Analysis Identifies WblA as a Pleiotropic Down-Regulator of Antibiotic Biosynthesis in Streptomyces

2007 ◽  
Vol 189 (11) ◽  
pp. 4315-4319 ◽  
Author(s):  
Seung-Hoon Kang ◽  
Jianqiang Huang ◽  
Han-Na Lee ◽  
Yoon-Ah Hur ◽  
Stanley N. Cohen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Microarray Analysis ◽  
Dna Microarray ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Morphological Differentiation ◽  
Antibiotic Biosynthesis ◽  
Gene Encoding ◽  
Putative Transcription Factor

ABSTRACT Using Streptomyces coelicolor microarrays to discover regulators of gene expression in other Streptomyces species, we identified wblA, a whiB-like gene encoding a putative transcription factor, as a down-regulator of doxorubicin biosynthesis in Streptomyces peucetius. Further analysis revealed that wblA functions pleiotropically to control antibiotic production and morphological differentiation in streptomycetes. Our results reveal a novel biological role for wblA and show the utility of interspecies microarray analysis for the investigation of streptomycete gene expression.

scholarly journals Membrane Association and Kinase-Like Motifs of the RamC Protein of Streptomyces coelicolor

2002 ◽  
Vol 184 (17) ◽  
pp. 4920-4924 ◽  
Author(s):  
Michael E. Hudson ◽  
Dachuan Zhang ◽  
Justin R. Nodwell
Keyword(s):  
Streptomyces Coelicolor ◽  
Membrane Association ◽  
Sequence Motifs ◽  
Filamentous Bacterium ◽  
Receptor Kinase ◽  
Null Mutant ◽  
Amino Terminal ◽  
Aerial Hyphae ◽  
Membrane Spanning

ABSTRACT The protein RamC is required for the production of the spore-forming cells called aerial hyphae by the filamentous bacterium Streptomyces coelicolor. We showed that RamC, which contains several weakly predicted membrane-spanning sequences, is located exclusively in the S. coelicolor membrane. By constructing site-directed mutants in the cloned ramC gene and complementing a ramC null mutant, we showed that protein kinase-like sequence motifs in the amino-terminal half of the protein are required for function in vivo. These data suggest that RamC is a membrane-associated receptor kinase.

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