Actinobacteria able to produce varieties of bioactive natural products have been long appreciated by the field of drug discovery and development.Recently,a few of CRISPR/Cas9 systems bearing different types of replico...Actinobacteria able to produce varieties of bioactive natural products have been long appreciated by the field of drug discovery and development.Recently,a few of CRISPR/Cas9 systems bearing different types of replicons(pSG5 and pIJ101)were developed to efficiently edit their genomes.Despite wide application in gene editing,their utility in editing challenging DNA regions e.g.high sequence identity has not been compared.In this study,we confirmed that the widely used temperature-sensitive pSG5 replicon is indeed not suitable for editing modular polyketide synthase(PKS)genes due to causing unpredicted gene recombination.This problem can be addressed by replacing the pSG5 with the segregationally unstable pIJ101 replicon.By introducing a counterselection marker CodA,convenient cloning sites in the single guide RNAs(sgRNAs)and homologous template scaffolds,we developed a new CRISPR-Cas9 system pMWCas9.This system was successfully used to delete/replace erythromycin PKS and other biosynthetic genes in Saccharopolyspora erythraea and Streptomyces sp.AL2110.By swapping the promoters of antB and antC with ermE and kasOp,we achieved a deacyl-antimycin hyper producer which produces a 9-fold higher yield than the original Streptomyces sp.AL2110 strain.Our results provide a robust and useful Cas9 tool for genetic studies in Actinobacteria.展开更多
Objective To study the antitumor components from an actinomycete strain(N2010-37) of bottom mud in Zhanjiang Mangrove,South China Sea.Methods The components were isolated and purified by chromatographic techniques and...Objective To study the antitumor components from an actinomycete strain(N2010-37) of bottom mud in Zhanjiang Mangrove,South China Sea.Methods The components were isolated and purified by chromatographic techniques and recrystallization,and the structures were identified by spectral methods together with physicochemical analyses.The antitumor effects of these components were tested in vitro by MTT method.Results Three compounds were identified including two anthrones and one novel lactone.They are(3S,4R,7R,8R,9S)-3,8-dihydroxy-4,7,9-trimethyl-2,6-cyclononanediolacetone(1) ,2-hydroxy-1-methoxy-3-methylanthraquinone(2) ,and 1,6,8-thihydroxy-3-methylanthraquinone(3) .Conclusion Compound 1 is a new compound,and compounds 1 and 3 show the favorable cytotoxic activities against human chronic granulocytic leukemia cell line K562 strain by MTT method in vitro.展开更多
In this paper, we report the design and moleculardocking study of analogues of antimycin A3 as inhibitors of anti-apoptotic Bcl-2 of breast cancer. Twenty designed compounds and the original antimycin A3 were docked b...In this paper, we report the design and moleculardocking study of analogues of antimycin A3 as inhibitors of anti-apoptotic Bcl-2 of breast cancer. Twenty designed compounds and the original antimycin A3 were docked based on their interaction with breast tumor receptor binding target Bcl-2. The docking resulted in the five top-ranked compounds, namely, compounds 11, 14, 15, 16, and 20, which have a lower G binding energy, better affinity and stronger hydrogen bonding interactions to the active site of Bcl-2 than antimycin A3. Among those five top-ranked compounds, analogue compounds 11 and 14, which have an 18-membered tetralactone core and 18-membered tetraol core, respectively, exhibited the strongest hydrogen bond interaction, formed high stability conformation, and demonstrated the greatest inhibitory activity on the catalytic site of Bcl-2.展开更多
基金This work was supported by the National Nature Science Foundation of China Grants(Nos.31570057,31430002,31320103911 and 31770063)Taishan Scholarship and“the Fundamental Research Funds for the Central Universities 22221818014.
文摘Actinobacteria able to produce varieties of bioactive natural products have been long appreciated by the field of drug discovery and development.Recently,a few of CRISPR/Cas9 systems bearing different types of replicons(pSG5 and pIJ101)were developed to efficiently edit their genomes.Despite wide application in gene editing,their utility in editing challenging DNA regions e.g.high sequence identity has not been compared.In this study,we confirmed that the widely used temperature-sensitive pSG5 replicon is indeed not suitable for editing modular polyketide synthase(PKS)genes due to causing unpredicted gene recombination.This problem can be addressed by replacing the pSG5 with the segregationally unstable pIJ101 replicon.By introducing a counterselection marker CodA,convenient cloning sites in the single guide RNAs(sgRNAs)and homologous template scaffolds,we developed a new CRISPR-Cas9 system pMWCas9.This system was successfully used to delete/replace erythromycin PKS and other biosynthetic genes in Saccharopolyspora erythraea and Streptomyces sp.AL2110.By swapping the promoters of antB and antC with ermE and kasOp,we achieved a deacyl-antimycin hyper producer which produces a 9-fold higher yield than the original Streptomyces sp.AL2110 strain.Our results provide a robust and useful Cas9 tool for genetic studies in Actinobacteria.
基金Foundation for Distinguished Young Talents in Higher Education of Guangdong,China (LYM09100)
文摘Objective To study the antitumor components from an actinomycete strain(N2010-37) of bottom mud in Zhanjiang Mangrove,South China Sea.Methods The components were isolated and purified by chromatographic techniques and recrystallization,and the structures were identified by spectral methods together with physicochemical analyses.The antitumor effects of these components were tested in vitro by MTT method.Results Three compounds were identified including two anthrones and one novel lactone.They are(3S,4R,7R,8R,9S)-3,8-dihydroxy-4,7,9-trimethyl-2,6-cyclononanediolacetone(1) ,2-hydroxy-1-methoxy-3-methylanthraquinone(2) ,and 1,6,8-thihydroxy-3-methylanthraquinone(3) .Conclusion Compound 1 is a new compound,and compounds 1 and 3 show the favorable cytotoxic activities against human chronic granulocytic leukemia cell line K562 strain by MTT method in vitro.
文摘In this paper, we report the design and moleculardocking study of analogues of antimycin A3 as inhibitors of anti-apoptotic Bcl-2 of breast cancer. Twenty designed compounds and the original antimycin A3 were docked based on their interaction with breast tumor receptor binding target Bcl-2. The docking resulted in the five top-ranked compounds, namely, compounds 11, 14, 15, 16, and 20, which have a lower G binding energy, better affinity and stronger hydrogen bonding interactions to the active site of Bcl-2 than antimycin A3. Among those five top-ranked compounds, analogue compounds 11 and 14, which have an 18-membered tetralactone core and 18-membered tetraol core, respectively, exhibited the strongest hydrogen bond interaction, formed high stability conformation, and demonstrated the greatest inhibitory activity on the catalytic site of Bcl-2.
