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Role of sgcR3 in positive regulation of enediyne antibiotic C-1027 production of Streptomyces globisporus C-1027.

Wang L, Hu Y, Zhang Y, Wang S, Cui Z, Bao Y, Jiang W, Hong B - BMC Microbiol. (2009)

Bottom Line: Overexpression of sgcR3 in S. globisporus C-1027 resulted in a 30-40% increase in C-1027 production.The role of SgcR3 has been proved to be a positive regulator of C-1027 biosynthesis in S. globisporus C-1027.SgcR3 occupies a higher level than SgcR1 and SgcR2 in the regulatory hierarchy that controls C-1027 production and activates the transcription of sgcR1 and sgcR2 by binding directly to the promoter region of sgcR1R2.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China. lifeiwang2002@hotmail.com

ABSTRACT

Background: C-1027, produced by Streptomyces globisporus C-1027, is one of the most potent antitumoral agents. The biosynthetic gene cluster of C-1027, previously cloned and sequenced, contains at least three putative regulatory genes, i.e. sgcR1, sgcR2 and sgcR3. The predicted gene products of these genes share sequence similarities to StrR, regulators of AraC/XylS family and TylR. The purpose of this study was to investigate the role of sgcR3 in C-1027 biosynthesis.

Results: Overexpression of sgcR3 in S. globisporus C-1027 resulted in a 30-40% increase in C-1027 production. Consistent with this, disruption of sgcR3 abolished C-1027 production. Complementation of the sgcR3-disrupted strain R3KO with intact sgcR3 gene could restore C-1027 production. The results from real time RT-PCR analysis in R3KO mutant and wild type strain indicated that not only transcripts of biosynthetic structural genes such as sgcA1 and sgcC4, but also putative regulatory genes, sgcR1 and sgcR2, were significantly decreased in R3KO mutant. The cross-complementation studies showed that sgcR1R2 could functionally complement sgcR3 disruption in trans. Purified N-terminal His10-tagged SgcR3 showed specific DNA-binding activity to the promoter region of sgcR1R2.

Conclusion: The role of SgcR3 has been proved to be a positive regulator of C-1027 biosynthesis in S. globisporus C-1027. SgcR3 occupies a higher level than SgcR1 and SgcR2 in the regulatory hierarchy that controls C-1027 production and activates the transcription of sgcR1 and sgcR2 by binding directly to the promoter region of sgcR1R2.

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Hypothetical schematic regulatory hierarchy of C-1027 biosynthesis in S. globisporus C-1027. Break line box with interrogation point represents unknown pathway-specific regulatory genes and break line arrow represents hypothetic feedback regulation. (+) indicates positive regulation and (?) indicates unknown possible regulation.
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Figure 8: Hypothetical schematic regulatory hierarchy of C-1027 biosynthesis in S. globisporus C-1027. Break line box with interrogation point represents unknown pathway-specific regulatory genes and break line arrow represents hypothetic feedback regulation. (+) indicates positive regulation and (?) indicates unknown possible regulation.

Mentions: This work is the first step in deciphering the regulatory factors involved in the biosynthesis of C-1027, and a primary model for pathway-specific regulation of C-1027 production is shown in Fig. 8. Therefore, precise roles for sgcR3, sgcR1, sgcR2 and other putative regulatory genes and their complex interaction remain to be defined. The data presented in this work set the stage for subsequent studies to delineate the complexity of the regulation of C-1027 biosynthesis, as well as for designing strategies for the construction of strains with enhanced C-1027 production.


Role of sgcR3 in positive regulation of enediyne antibiotic C-1027 production of Streptomyces globisporus C-1027.

Wang L, Hu Y, Zhang Y, Wang S, Cui Z, Bao Y, Jiang W, Hong B - BMC Microbiol. (2009)

Hypothetical schematic regulatory hierarchy of C-1027 biosynthesis in S. globisporus C-1027. Break line box with interrogation point represents unknown pathway-specific regulatory genes and break line arrow represents hypothetic feedback regulation. (+) indicates positive regulation and (?) indicates unknown possible regulation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2657911&req=5

Figure 8: Hypothetical schematic regulatory hierarchy of C-1027 biosynthesis in S. globisporus C-1027. Break line box with interrogation point represents unknown pathway-specific regulatory genes and break line arrow represents hypothetic feedback regulation. (+) indicates positive regulation and (?) indicates unknown possible regulation.
Mentions: This work is the first step in deciphering the regulatory factors involved in the biosynthesis of C-1027, and a primary model for pathway-specific regulation of C-1027 production is shown in Fig. 8. Therefore, precise roles for sgcR3, sgcR1, sgcR2 and other putative regulatory genes and their complex interaction remain to be defined. The data presented in this work set the stage for subsequent studies to delineate the complexity of the regulation of C-1027 biosynthesis, as well as for designing strategies for the construction of strains with enhanced C-1027 production.

Bottom Line: Overexpression of sgcR3 in S. globisporus C-1027 resulted in a 30-40% increase in C-1027 production.The role of SgcR3 has been proved to be a positive regulator of C-1027 biosynthesis in S. globisporus C-1027.SgcR3 occupies a higher level than SgcR1 and SgcR2 in the regulatory hierarchy that controls C-1027 production and activates the transcription of sgcR1 and sgcR2 by binding directly to the promoter region of sgcR1R2.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, PR China. lifeiwang2002@hotmail.com

ABSTRACT

Background: C-1027, produced by Streptomyces globisporus C-1027, is one of the most potent antitumoral agents. The biosynthetic gene cluster of C-1027, previously cloned and sequenced, contains at least three putative regulatory genes, i.e. sgcR1, sgcR2 and sgcR3. The predicted gene products of these genes share sequence similarities to StrR, regulators of AraC/XylS family and TylR. The purpose of this study was to investigate the role of sgcR3 in C-1027 biosynthesis.

Results: Overexpression of sgcR3 in S. globisporus C-1027 resulted in a 30-40% increase in C-1027 production. Consistent with this, disruption of sgcR3 abolished C-1027 production. Complementation of the sgcR3-disrupted strain R3KO with intact sgcR3 gene could restore C-1027 production. The results from real time RT-PCR analysis in R3KO mutant and wild type strain indicated that not only transcripts of biosynthetic structural genes such as sgcA1 and sgcC4, but also putative regulatory genes, sgcR1 and sgcR2, were significantly decreased in R3KO mutant. The cross-complementation studies showed that sgcR1R2 could functionally complement sgcR3 disruption in trans. Purified N-terminal His10-tagged SgcR3 showed specific DNA-binding activity to the promoter region of sgcR1R2.

Conclusion: The role of SgcR3 has been proved to be a positive regulator of C-1027 biosynthesis in S. globisporus C-1027. SgcR3 occupies a higher level than SgcR1 and SgcR2 in the regulatory hierarchy that controls C-1027 production and activates the transcription of sgcR1 and sgcR2 by binding directly to the promoter region of sgcR1R2.

Show MeSH
Related in: MedlinePlus