Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds
ABSTRACT Advances in genome sequencing have revitalized natural product discovery efforts, revealing the untapped biosynthetic potential of fungi. While the volume of genomic data continues to expand, discovery efforts are slowed due to the time-consuming nature of experiments required to characteri...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Society for Microbiology
2020-08-01
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| Series: | mBio |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.01691-20 |
| _version_ | 1818424662654189568 |
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| author | Lindsay K. Caesar Matthew T. Robey Michael Swyers Md N. Islam Rosa Ye Purav P. Vagadia Gary E. Schiltz Paul M. Thomas Chengcang C. Wu Neil L. Kelleher Nancy P. Keller Jin Woo Bok |
| author_facet | Lindsay K. Caesar Matthew T. Robey Michael Swyers Md N. Islam Rosa Ye Purav P. Vagadia Gary E. Schiltz Paul M. Thomas Chengcang C. Wu Neil L. Kelleher Nancy P. Keller Jin Woo Bok |
| author_sort | Lindsay K. Caesar |
| collection | DOAJ |
| description | ABSTRACT Advances in genome sequencing have revitalized natural product discovery efforts, revealing the untapped biosynthetic potential of fungi. While the volume of genomic data continues to expand, discovery efforts are slowed due to the time-consuming nature of experiments required to characterize new molecules. To direct efforts toward uncharacterized biosynthetic gene clusters most likely to encode novel chemical scaffolds, we took advantage of comparative metabolomics and heterologous gene expression using fungal artificial chromosomes (FACs). By linking mass spectral profiles with structural clues provided by FAC-encoded gene clusters, we targeted a compound originating from an unusual gene cluster containing an indoleamine 2,3-dioxygenase (IDO). With this approach, we isolate and characterize R and S forms of the new molecule terreazepine, which contains a novel chemical scaffold resulting from cyclization of the IDO-supplied kynurenine. The discovery of terreazepine illustrates that FAC-based approaches targeting unusual biosynthetic machinery provide a promising avenue forward for targeted discovery of novel scaffolds and their biosynthetic enzymes, and it also represents another example of a biosynthetic gene cluster “repurposing” a primary metabolic enzyme to diversify its secondary metabolite arsenal. IMPORTANCE Here, we provide evidence that Aspergillus terreus encodes a biosynthetic gene cluster containing a repurposed indoleamine 2,3-dioxygenase (IDO) dedicated to secondary metabolite synthesis. The discovery of this neofunctionalized IDO not only enabled discovery of a new compound with an unusual chemical scaffold but also provided insight into the numerous strategies fungi employ for diversifying and protecting themselves against secondary metabolites. The observations in this study set the stage for further in-depth studies into the function of duplicated IDOs present in fungal biosynthetic gene clusters and presents a strategy for accessing the biosynthetic potential of gene clusters containing duplicated primary metabolic genes. |
| first_indexed | 2024-12-14T14:01:37Z |
| format | Article |
| id | doaj.art-0c3cdc60038744a98df4944edd8388aa |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-14T14:01:37Z |
| publishDate | 2020-08-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-0c3cdc60038744a98df4944edd8388aa2022-12-21T22:58:42ZengAmerican Society for MicrobiologymBio2150-75112020-08-0111410.1128/mBio.01691-20Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical ScaffoldsLindsay K. Caesar0Matthew T. Robey1Michael Swyers2Md N. Islam3Rosa Ye4Purav P. Vagadia5Gary E. Schiltz6Paul M. Thomas7Chengcang C. Wu8Neil L. Kelleher9Nancy P. Keller10Jin Woo Bok11Department of Chemistry, Northwestern University, Evanston, Illinois, USADepartment of Molecular Biosciences, Northwestern University, Evanston, Illinois, USAIntact Genomics, Inc., St. Louis, Missouri, USAIntact Genomics, Inc., St. Louis, Missouri, USAIntact Genomics, Inc., St. Louis, Missouri, USACenter for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USACenter for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USADepartment of Molecular Biosciences, Northwestern University, Evanston, Illinois, USAIntact Genomics, Inc., St. Louis, Missouri, USADepartment of Chemistry, Northwestern University, Evanston, Illinois, USADepartment of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, USADepartment of Medical Microbiology and Immunology, University of Wisconsin—Madison, Madison, Wisconsin, USAABSTRACT Advances in genome sequencing have revitalized natural product discovery efforts, revealing the untapped biosynthetic potential of fungi. While the volume of genomic data continues to expand, discovery efforts are slowed due to the time-consuming nature of experiments required to characterize new molecules. To direct efforts toward uncharacterized biosynthetic gene clusters most likely to encode novel chemical scaffolds, we took advantage of comparative metabolomics and heterologous gene expression using fungal artificial chromosomes (FACs). By linking mass spectral profiles with structural clues provided by FAC-encoded gene clusters, we targeted a compound originating from an unusual gene cluster containing an indoleamine 2,3-dioxygenase (IDO). With this approach, we isolate and characterize R and S forms of the new molecule terreazepine, which contains a novel chemical scaffold resulting from cyclization of the IDO-supplied kynurenine. The discovery of terreazepine illustrates that FAC-based approaches targeting unusual biosynthetic machinery provide a promising avenue forward for targeted discovery of novel scaffolds and their biosynthetic enzymes, and it also represents another example of a biosynthetic gene cluster “repurposing” a primary metabolic enzyme to diversify its secondary metabolite arsenal. IMPORTANCE Here, we provide evidence that Aspergillus terreus encodes a biosynthetic gene cluster containing a repurposed indoleamine 2,3-dioxygenase (IDO) dedicated to secondary metabolite synthesis. The discovery of this neofunctionalized IDO not only enabled discovery of a new compound with an unusual chemical scaffold but also provided insight into the numerous strategies fungi employ for diversifying and protecting themselves against secondary metabolites. The observations in this study set the stage for further in-depth studies into the function of duplicated IDOs present in fungal biosynthetic gene clusters and presents a strategy for accessing the biosynthetic potential of gene clusters containing duplicated primary metabolic genes.https://journals.asm.org/doi/10.1128/mBio.01691-20IDOheterologous expressionnatural productsAspergillus terreusAspergillus nidulansgenome mining |
| spellingShingle | Lindsay K. Caesar Matthew T. Robey Michael Swyers Md N. Islam Rosa Ye Purav P. Vagadia Gary E. Schiltz Paul M. Thomas Chengcang C. Wu Neil L. Kelleher Nancy P. Keller Jin Woo Bok Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds mBio IDO heterologous expression natural products Aspergillus terreus Aspergillus nidulans genome mining |
| title | Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds |
| title_full | Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds |
| title_fullStr | Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds |
| title_full_unstemmed | Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds |
| title_short | Heterologous Expression of the Unusual Terreazepine Biosynthetic Gene Cluster Reveals a Promising Approach for Identifying New Chemical Scaffolds |
| title_sort | heterologous expression of the unusual terreazepine biosynthetic gene cluster reveals a promising approach for identifying new chemical scaffolds |
| topic | IDO heterologous expression natural products Aspergillus terreus Aspergillus nidulans genome mining |
| url | https://journals.asm.org/doi/10.1128/mBio.01691-20 |
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