The pleitropic regulator AdpAch is required for natamycin biosynthesis and morphological differentiation in Streptomyces chattanoogensis

Microbiology ◽  
2011 ◽  
Vol 157 (5) ◽  
pp. 1300-1311 ◽  
Author(s):  
Yi-Ling Du ◽  
Shan-Zhen Li ◽  
Zhan Zhou ◽  
Shi-Fei Chen ◽  
Wei-Ming Fan ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Regulatory Gene ◽  
Gene Clusters ◽  
Transcriptional Analysis ◽  
Pcr Analysis ◽  
Biosynthetic Gene ◽  
Coding Region ◽  
Mobility Shift ◽  
Intergenic Regions ◽  
Streptomyces Chattanoogensis

The complete natamycin (NTM) biosynthetic gene cluster of Streptomyces chattanoogensis was cloned and confirmed by the disruption of pathway-specific activator genes. Comparative cluster analysis with its counterpart in Streptomyces natalensis revealed different cluster architecture between these two clusters. Compared with the highly conserved coding sequences, sequence variations appear to occur frequently in the intergenic regions. The evolutionary change of nucleotide sequence in the intergenic regions has given rise to different transcriptional organizations in the two clusters and resulted in altered gene regulation. These results provide insight into the evolution of antibiotic biosynthetic gene clusters. In addition, we cloned a pleitropic regulator gene, adpAch , in S. chattanoogensis. Using the genetic system that we developed for this strain, adpAch was deleted from the genome of S. chattanoogensis. The ΔadpAch mutant showed a conditionally sparse aerial mycelium formation phenotype and defects in sporulation; it also lost the ability to produce NTM and a diffusible yellow pigment normally produced by S. chattanoogensis. RT-PCR analysis revealed that transcription of adpAch was constitutive in YEME liquid medium. By using rapid amplification of 5′ complementary DNA ends, two transcription start sites were identified upstream of the adpAch coding region. Quantitative transcriptional analysis showed that the expression level of the NTM regulatory gene scnRI decreased 20-fold in the ΔadpAch mutant strain, while the transcription of the other activator gene scnRII was not significantly affected. Electrophoretic mobility shift assay (EMSA) showed that AdpAch binds to its own promoter but fails to bind to the promoter region of scnRI, indicating that the control of scnRI by AdpAch is exerted in an indirect way. This work not only provides a platform and a new potential target for increasing the titre of NTM by genetic manipulation, but also advances the understanding of the regulation of NTM biosynthesis.

scholarly journals Combining QTL-seq and linkage mapping to fine map a candidate gene in qCTS6 for cold tolerance at the seedling stage in rice

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Luomiao Yang ◽  
Jingguo Wang ◽  
Zhenghong Han ◽  
Lei Lei ◽  
Hua Long Liu ◽  
...  
Keyword(s):  
Cold Stress ◽  
Cold Tolerance ◽  
Regulatory Gene ◽  
Snp Markers ◽  
Seedling Stage ◽  
Pcr Analysis ◽  
Sequencing Data ◽  
Coding Region ◽  
Rice Varieties ◽  
Major Qtl

Abstract Background Cold stress caused by low temperatures is an important factor restricting rice production. Identification of cold-tolerance genes that can stably express in cold environments is crucial for molecular rice breeding. Results In this study, we employed high-throughput quantitative trait locus sequencing (QTL-seq) analyses in a 460-individual F2:3 mapping population to identify major QTL genomic regions governing cold tolerance at the seedling stage in rice. A novel major QTL (qCTS6) controlling the survival rate (SR) under low-temperature conditions of 9°C/10 days was mapped on the 2.60-Mb interval on chromosome 6. Twenty-seven single-nucleotide polymorphism (SNP) markers were designed for the qCST6 region based on re-sequencing data, and local QTL mapping was conducted using traditional linkage analysis. Eventually, we mapped qCTS6 to a 96.6-kb region containing 13 annotated genes, of which seven predicted genes contained 13 non-synonymous SNP loci. Quantitative reverse transcription PCR analysis revealed that only Os06g0719500, an OsbZIP54 transcription factor, was strongly induced by cold stress. Haplotype analysis confirmed that +376 bp (T>A) in the OsbZIP54 coding region played a key role in regulating cold tolerance in rice. Conclusion We identified OsbZIP54 as a novel regulatory gene associated with rice cold-responsive traits, with its Dongfu-104 allele showing specific cold-induction expression serving as an important molecular variation for rice improvement. This result is expected to further exploration of the genetic mechanism of rice cold tolerance at the seedling stage and improve cold tolerance in rice varieties by marker-assisted selection.

scholarly journals New Insights into the Genetic Organization of the FK228 Biosynthetic Gene Cluster inChromobacterium violaceumNo. 968

2010 ◽  
Vol 77 (4) ◽  
pp. 1508-1511 ◽  
Author(s):  
Vishwakanth Y. Potharla ◽  
Shane R. Wesener ◽  
Yi-Qiang Cheng
Keyword(s):  
Natural Product ◽  
Gene Cluster ◽  
Gene Deletion ◽  
Regulatory Gene ◽  
Biosynthetic Gene Cluster ◽  
Transcriptional Analysis ◽  
Biosynthetic Gene ◽  
Genetic Organization

ABSTRACTThe biosynthetic gene cluster of FK228, an FDA-approved anticancer natural product, was identified and sequenced previously. The genetic organization of this gene cluster has now been delineated through systematic gene deletion and transcriptional analysis. As a result, the gene cluster is redefined to contain 12 genes:depAthroughdepJ,depM, and a newly identified pathway regulatory gene,depR.

scholarly journals Challenges and Advances in Genome Editing Technologies in Streptomyces

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 734 ◽  
Author(s):  
Yawei Zhao ◽  
Guoquan Li ◽  
Yunliang Chen ◽  
Yinhua Lu
Keyword(s):  
Natural Product ◽  
Genome Editing ◽  
Genetic Manipulation ◽  
Chemical Compounds ◽  
Gene Clusters ◽  
Future Research ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Research Focus ◽  
Experimental Conditions

The genome of Streptomyces encodes a high number of natural product (NP) biosynthetic gene clusters (BGCs). Most of these BGCs are not expressed or are poorly expressed (commonly called silent BGCs) under traditional laboratory experimental conditions. These NP BGCs represent an unexplored rich reservoir of natural compounds, which can be used to discover novel chemical compounds. To activate silent BGCs for NP discovery, two main strategies, including the induction of BGCs expression in native hosts and heterologous expression of BGCs in surrogate Streptomyces hosts, have been adopted, which normally requires genetic manipulation. So far, various genome editing technologies have been developed, which has markedly facilitated the activation of BGCs and NP overproduction in their native hosts, as well as in heterologous Streptomyces hosts. In this review, we summarize the challenges and recent advances in genome editing tools for Streptomyces genetic manipulation with a focus on editing tools based on clustered regularly interspaced short palindrome repeat (CRISPR)/CRISPR-associated protein (Cas) systems. Additionally, we discuss the future research focus, especially the development of endogenous CRISPR/Cas-based genome editing technologies in Streptomyces.

scholarly journals Whole-genome sequence of bioactive streptomycete derived from mangrove forest in Malaysia, Streptomyces sp. MUSC 14

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hooi-Leng Ser ◽  
Loh Teng-Hern Tan ◽  
Wen-Si Tan ◽  
Wai-Fong Yin ◽  
Kok-Gan Chan
Keyword(s):  
East Coast ◽  
Genetic Manipulation ◽  
Genome Mining ◽  
Gene Clusters ◽  
Peninsular Malaysia ◽  
Whole Genome Sequence ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Streptomyces Sp ◽  
A Genome

The contribution of streptomycetes to human health is undeniably important and significant, given that these filamentous microbes can produce interesting compounds that can be used to cure deadly infections and even cancer. Isolated from the east coast of Peninsular Malaysia, Streptomyces sp. MUSC 14 has shown significant antioxidant capacity. The current study explores the genomic potential of MUSC 14 via a genome mining approach. The genome size of MUSC 14 is 10,274,825 bp with G + C content of 71.3 %. AntiSMASH analysis revealed a total of nine biosynthetic gene clusters (with more than 80 % similarities to known gene clusters). This information serves as an important foundation for subsequent studies, particularly the purification and isolation of bioactive compounds by genetic manipulation techniques.

scholarly journals Comparative transcriptomics as a guide to natural product discovery and biosynthetic gene cluster functionality

2017 ◽  
Vol 114 (52) ◽  
pp. E11121-E11130 ◽  
Author(s):  
Gregory C. A. Amos ◽  
Takayoshi Awakawa ◽  
Robert N. Tuttle ◽  
Anne-Catrin Letzel ◽  
Min Cheol Kim ◽  
...  
Keyword(s):  
Natural Product ◽  
Gene Cluster ◽  
Genetic Manipulation ◽  
Expression Profiles ◽  
Genome Mining ◽  
Gene Clusters ◽  
Comparative Transcriptomics ◽  
Regulatory Control ◽  
Biosynthetic Gene ◽  
Metabolomics Data

Bacterial natural products remain an important source of new medicines. DNA sequencing has revealed that a majority of natural product biosynthetic gene clusters (BGCs) maintained in bacterial genomes have yet to be linked to the small molecules whose biosynthesis they encode. Efforts to discover the products of these orphan BGCs are driving the development of genome mining techniques based on the premise that many are transcriptionally silent during normal laboratory cultivation. Here, we employ comparative transcriptomics to assess BGC expression among four closely related strains of marine bacteria belonging to the genusSalinispora. The results reveal that slightly more than half of the BGCs are expressed at levels that should facilitate product detection. By comparing the expression profiles of similar gene clusters in different strains, we identified regulatory genes whose inactivation appears linked to cluster silencing. The significance of these subtle differences between expressed and silent BGCs could not have been predicted a priori and was only revealed by comparative transcriptomics. Evidence for the conservation of silent clusters among a larger number of strains for which genome sequences are available suggests they may be under different regulatory control from the expressed forms or that silencing may represent an underappreciated mechanism of gene cluster evolution. Coupling gene expression and metabolomics data established a bioinformatic link between the salinipostins and their associated BGC, while genetic manipulation established the genetic basis for this series of compounds, which were previously unknown fromSalinispora pacifica.

scholarly journals Genomics-Driven Activation of Silent Biosynthetic Gene Clusters in Burkholderia gladioli by Screening Recombineering System

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 700
Author(s):  
Hanna Chen ◽  
Tao Sun ◽  
Xianping Bai ◽  
Jie Yang ◽  
Fu Yan ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Structural Diversity ◽  
Gene Clusters ◽  
Unnatural Amino Acid ◽  
Biosynthetic Gene ◽  
Assembly Lines ◽  
Biosynthetic Gene Clusters ◽  
Genome Modification ◽  
Burkholderia Gladioli ◽  
Peptide Synthetase

The Burkholderia genus possesses ecological and metabolic diversities. A large number of silent biosynthetic gene clusters (BGCs) in the Burkholderia genome remain uncharacterized and represent a promising resource for new natural product discovery. However, exploitation of the metabolomic potential of Burkholderia is limited by the absence of efficient genetic manipulation tools. Here, we screened a bacteriophage recombinase system Redγ-BAS, which was functional for genome modification in the plant pathogen Burkholderia gladioli ATCC 10248. By using this recombineering tool, the constitutive promoters were precisely inserted in the genome, leading to activation of two silent nonribosomal peptide synthetase gene clusters (bgdd and hgdd) and production of corresponding new classes of lipopeptides, burriogladiodins A–H (1–8) and haereogladiodins A–B (9–10). Structure elucidation revealed an unnatural amino acid Z- dehydrobutyrine (Dhb) in 1–8 and an E-Dhb in 9–10. Notably, compounds 2–4 and 9 feature an unusual threonine tag that is longer than the predicted collinearity assembly lines. The structural diversity of burriogladiodins was derived from the relaxed substrate specificity of the fifth adenylation domain as well as chain termination conducted by water or threonine. The recombinase-mediating genome editing system is not only applicable in B. gladioli, but also possesses great potential for mining meaningful silent gene clusters from other Burkholderia species.

scholarly journals Microbiological and molecular insights on rare Actinobacteria harboring bioactive prospective

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Dina H. Amin ◽  
Nagwa A. Abdallah ◽  
Assem Abolmaaty ◽  
Sahar Tolba ◽  
Elizabeth M. H. Wellington
Keyword(s):  
Bioinformatics Analysis ◽  
Genetic Manipulation ◽  
Antibiotic Production ◽  
Gene Clusters ◽  
Bioactive Molecules ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Pcr Screening ◽  
Molecular Approaches ◽  
Shed Light

Abstract Background Actinobacteria is as a group of advanced filamentous bacteria. Rare Actinobacteria are of special interest as they are rarely isolated from the environments. They are a major source of important bioactive compounds. Determining the proper strategy for the identification of Actinobacteria harboring biosynthetic gene clusters and producing bioactive molecules is a challenging platform. Methodology In this review, we discuss a consequence of microbiological and molecular methods for the identification of rare Actinobacteria. In addition to that, we shed light on rare Actinobacteria’s significance in antibiotic production. We also clarified molecular approaches for the manipulation of novel biosynthetic gene clusters via PCR screening, fosmid libraries, and Illumina whole-genome sequencing in combination with bioinformatics analysis. Conclusion Perceptions of the conventional and molecular identification of Actinobacteria were conducted. This will open the door for the genetic manipulation of novel antibiotic gene clusters in heterologous hosts. Also, these conclusions will lead to constructing new bioactive molecules via genetically engineering biosynthetic pathways.

scholarly journals Systematic characterization of a novel gal operon in Thermoanaerobacter tengcongensis

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1717-1725 ◽  
Author(s):  
Zhong Qian ◽  
Bo Meng ◽  
Quanhui Wang ◽  
Zhuowei Wang ◽  
Chuanqi Zhou ◽  
...  
Keyword(s):  
Hypothetical Protein ◽  
Biochemical Properties ◽  
Pcr Analysis ◽  
Mobility Shift ◽  
Thermoanaerobacter Tengcongensis ◽  
Different Temperatures ◽  
Intergenic Regions ◽  
Mobility Shift Assay ◽  
Operon Expression ◽  
Transcriptional Start Sites

On the basis of the Thermoanaerobacter tengcongensis genome, a novel type of gal operon was deduced. The gene expression and biochemical properties of this operon were further characterized. RT-PCR analysis of the intergenic regions suggested that the transcription of the gal operon was continuous. With gene cloning and enzyme activity assays, TTE1929, TTE1928 and TTE1927 were identified to be GalT, GalK and GalE, respectively. Results elicited from polarimetry assays revealed that TTE1925, a hypothetical protein, was a novel mutarotase, termed MR-Tt. TTE1926 was identified as a regulator that could bind to two operators in the operon promoter. The transcriptional start sites were mapped, and this suggested that there are two promoters in this operon. Expression of the gal genes was significantly induced by galactose, whereas only MR-Tt expression was detected in glucose-cultured T. tengcongensis at both the mRNA and the protein level. In addition, the abundance of gal proteins was examined at different temperatures. At temperatures ranging from 60 to 80 °C, the level of MR-Tt protein was relatively stable, but that of the other gal proteins was dramatically decreased. The operator-binding complexes were isolated and identified by electrophoretic mobility shift assay-liquid chromatography (EMSA-LC) MS-MS, which suggested that several regulatory proteins, such as GalR and a sensory histidine kinase, participate in the regulation of the gal operon.

scholarly journals A Hierarchical Network of Four Regulatory Genes Controlling Production of the Polyene Antibiotic Candicidin in Streptomyces sp. Strain FR-008

2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Yanping Zhu ◽  
Wenhao Xu ◽  
Jing Zhang ◽  
Peipei Zhang ◽  
Zhilong Zhao ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Regulatory Network ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Regulatory Genes ◽  
Transcriptional Analysis ◽  
Antibiotic Biosynthesis ◽  
Biosynthetic Gene ◽  
Polyene Antibiotic ◽  
Biosynthetic Gene Clusters

ABSTRACT The four regulatory genes fscR1 to fscR4 in Streptomyces sp. strain FR-008 form a genetic arrangement that is widely distributed in macrolide-producing bacteria. Our previous work has demonstrated that fscR1 and fscR4 are critical for production of the polyene antibiotic candicidin. In this study, we further characterized the roles of the other two regulatory genes, fscR2 and fscR3, focusing on the relationship between these four regulatory genes. Disruption of a single or multiple regulatory genes did not affect bacterial growth, but transcription of genes in the candicidin biosynthetic gene cluster decreased, and candicidin production was abolished, indicating a critical role for each of the four regulatory genes, including fscR2 and fscR3, in candicidin biosynthesis. We found that fscR1 to fscR4, although differentially expressed throughout the growth phase, displayed similar temporal expression patterns, with an abrupt increase in the early exponential phase, coincident with initial detection of antibiotic production in the same phase. Our data suggest that the four regulatory genes fscR1 to fscR4 have various degrees of control over structural genes in the biosynthetic cluster under the conditions examined. Extensive transcriptional analysis indicated that complex regulation exists between these four regulatory genes, forming a regulatory network, with fscR1 and fscR4 functioning at a lower level. Comprehensive cross-complementation analysis indicates that functional complementation is restricted among the four regulators and unidirectional, with fscR1 complementing the loss of fscR3 or -4 and fscR4 complementing loss of fscR2. Our study provides more insights into the roles of, and the regulatory network formed by, these four regulatory genes controlling production of an important pharmaceutical compound. IMPORTANCE The regulation of antibiotic biosynthesis by Streptomyces species is complex, especially for biosynthetic gene clusters with multiple regulatory genes. The biosynthetic gene cluster for the polyene antibiotic candicidin contains four consecutive regulatory genes, which encode regulatory proteins from different families and which form a subcluster within the larger biosynthetic gene cluster in Streptomyces sp. FR-008. Syntenic arrangements of these regulatory genes are widely distributed in polyene gene clusters, such as the amphotericin and nystatin gene clusters, suggesting a conserved regulatory mechanism controlling production of these clinically important medicines. However, the relationships between these multiple regulatory genes are unknown. In this study, we determined that each of these four regulatory genes is critical for candicidin production. Additionally, using transcriptional analyses, bioassays, high-performance liquid chromatography (HPLC) analysis, and genetic cross-complementation, we showed that FscR1 to FscR4 comprise a hierarchical regulatory network that controls candicidin production and is likely representative of how expression of other polyene biosynthetic gene clusters is controlled.

scholarly journals Gene Modules Co-regulated with Biosynthetic Gene Clusters for Allelopathy between Rice and Barnyardgrass

2019 ◽  
Vol 20 (16) ◽  
pp. 3846 ◽  
Author(s):  
Most. Humaira Sultana ◽  
Fangjie Liu ◽  
Md. Alamin ◽  
Lingfeng Mao ◽  
Lei Jia ◽  
...  
Keyword(s):  
Gene Networks ◽  
Regulatory Gene ◽  
Crop Protection ◽  
Gene Clusters ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Central Process ◽  
Coordinated Expression ◽  
Gene Modules ◽  
Allelopathic Interactions

Allelopathy is a central process in crop–weed interactions and is mediated by the release of allelochemicals that result in adverse growth effects on one or the other plant in the interaction. The genomic mechanism for the biosynthesis of many critical allelochemicals is unknown but may involve the clustering of non-homologous biosynthetic genes involved in their formation and regulatory gene modules involved in controlling the coordinated expression within these gene clusters. In this study, we used the transcriptomes from mono- or co-cultured rice and barnyardgrass to investigate the nature of the gene clusters and their regulatory gene modules involved in the allelopathic interactions of these two plants. In addition to the already known biosynthetic gene clusters in barnyardgrass we identified three potential new clusters including one for quercetin biosynthesis and potentially involved in allelopathic interaction with rice. Based on the construction of gene networks, we identified one gene regulatory module containing hub transcription factors, significantly positively co-regulated with both the momilactone A and phytocassane clusters in rice. In barnyardgrass, gene modules and hub genes co-expressed with the gene clusters responsible for 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) biosynthesis were also identified. In addition, we found three genes in barnyardgrass encoding indole-3-glycerolphosphate synthase that regulate the expression of the DIMBOA cluster. Our findings offer new insights into the regulatory mechanisms of biosynthetic gene clusters involved in allelopathic interactions between rice and barnyardgrass, and have potential implications in controlling weeds for crop protection.

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