Dalbavancin is a novel glycopeptide antibiotic with activity against a broad range of Gram-positive bacteria,including methicillin-resistant Staphylococcus aureus(MRSA).A40926B0 is the direct precursor of dalbavancin,...Dalbavancin is a novel glycopeptide antibiotic with activity against a broad range of Gram-positive bacteria,including methicillin-resistant Staphylococcus aureus(MRSA).A40926B0 is the direct precursor of dalbavancin,but the regulatory mechanisms underlying its biosynthesis are not well understood.Additionally,the presence of seven homologs leads to significant metabolic burden,affecting both production and purity of A40926B0.To further reveal the transcriptional regulatory mechanism of A40926B0 biosynthesis in N.gerenzanensis L70,this study employed multiple strategies to explore the regulatory network of its biosynthesis from both intracluster and extracluster aspects.WblA regulates gene expression within and outside the biosynthetic gene cluster(BGC),impacting multiple biosynthetic pathways,and Dbv3,a key regulator in the A40926B0 cluster,positively in-fluences biosynthesis.Using a bottom-up(DNA to protein)regulator mining strategy with the key intra-cluster regulator Dbv3,it was determined that GlnR is also involved in the regulation of secondary metabolism,while BkdR regulates precursor supply.By constructing the combination of GlnR,BkdR and Dbv3 together with the WblA deletion,the regulatory network of A40926B0 was reconstructed,resulting in a 92%improvement in purity of A40926B0.The objective of this study is to elucidate the regulatory mechanisms governing A40926B0 biosynthesis by constructing a comprehensive,multidimensional model of its regulatory network.The findings of this study serve to enhance our comprehension of A40926B0 biosynthesis and furnish insights into broader strategies for enhancing the production of other natural products and secondary metabolites in industrial microbiology.展开更多
Genome sequencing has revealed that actinomycetes possess the potential to produce many more secondary metabolites than previously thought.The existing challenge is to devise efficient methods to activate these silent...Genome sequencing has revealed that actinomycetes possess the potential to produce many more secondary metabolites than previously thought.The existing challenge is to devise efficient methods to activate these silent biosynthetic gene clusters(BGCs).In Streptomyces ansochromogenes,disruption of wbl A,a pleiotropic regulatory gene,activated the expression of cryptic tylosin analogues and abolished nikkomycin production simultaneously.Overexpressing pathway-specific regulatory genes tylR1 and tylR2 can also trigger the biosynthesis of silent tylosin analogues,in which TylR1 exerted its function via enhancing tylR2 expression.Bacterial one-hybrid system experiments unveiled that Wbl A directly inhibits the transcription of tylR1 and tylR2 to result in the silence of tylosin analogues BGC.Furthermore,Wbl A can activate the nikkomycin production through up-regulating the transcription of pleiotropic regulatory gene adp A.More interestingly,Adp A can activate san G(an activator gene in nikkomycin BGC)but repress wbl A.Our studies provide a valuable insight into the complex functions of pleiotropic regulators.展开更多
基金supported by the National Natural Science Foundation of China(grant number 32170057).
文摘Dalbavancin is a novel glycopeptide antibiotic with activity against a broad range of Gram-positive bacteria,including methicillin-resistant Staphylococcus aureus(MRSA).A40926B0 is the direct precursor of dalbavancin,but the regulatory mechanisms underlying its biosynthesis are not well understood.Additionally,the presence of seven homologs leads to significant metabolic burden,affecting both production and purity of A40926B0.To further reveal the transcriptional regulatory mechanism of A40926B0 biosynthesis in N.gerenzanensis L70,this study employed multiple strategies to explore the regulatory network of its biosynthesis from both intracluster and extracluster aspects.WblA regulates gene expression within and outside the biosynthetic gene cluster(BGC),impacting multiple biosynthetic pathways,and Dbv3,a key regulator in the A40926B0 cluster,positively in-fluences biosynthesis.Using a bottom-up(DNA to protein)regulator mining strategy with the key intra-cluster regulator Dbv3,it was determined that GlnR is also involved in the regulation of secondary metabolism,while BkdR regulates precursor supply.By constructing the combination of GlnR,BkdR and Dbv3 together with the WblA deletion,the regulatory network of A40926B0 was reconstructed,resulting in a 92%improvement in purity of A40926B0.The objective of this study is to elucidate the regulatory mechanisms governing A40926B0 biosynthesis by constructing a comprehensive,multidimensional model of its regulatory network.The findings of this study serve to enhance our comprehension of A40926B0 biosynthesis and furnish insights into broader strategies for enhancing the production of other natural products and secondary metabolites in industrial microbiology.
基金supported by the National Key Research and Development Program of China(2020YFA0907800)the National Natural Science Foundation of China(32170043,82173720)the Beijing Natural Science Foundation(7212153)。
文摘Genome sequencing has revealed that actinomycetes possess the potential to produce many more secondary metabolites than previously thought.The existing challenge is to devise efficient methods to activate these silent biosynthetic gene clusters(BGCs).In Streptomyces ansochromogenes,disruption of wbl A,a pleiotropic regulatory gene,activated the expression of cryptic tylosin analogues and abolished nikkomycin production simultaneously.Overexpressing pathway-specific regulatory genes tylR1 and tylR2 can also trigger the biosynthesis of silent tylosin analogues,in which TylR1 exerted its function via enhancing tylR2 expression.Bacterial one-hybrid system experiments unveiled that Wbl A directly inhibits the transcription of tylR1 and tylR2 to result in the silence of tylosin analogues BGC.Furthermore,Wbl A can activate the nikkomycin production through up-regulating the transcription of pleiotropic regulatory gene adp A.More interestingly,Adp A can activate san G(an activator gene in nikkomycin BGC)but repress wbl A.Our studies provide a valuable insight into the complex functions of pleiotropic regulators.
