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Long-chain N-acyltyrosine synthases from environmental DNA
Sean F Brady1, Carol J Chao, Jon Clardy
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Applied and Environmental Microbiology
|November 6, 2004
Summary
Environmental DNA (eDNA) expression in microbes unlocks access to novel natural products. Researchers discovered common long-chain N-acyltyrosines, previously unknown from cultured bacteria, using eDNA libraries.
Area of Science:
- Microbiology
- Natural Product Discovery
- Metagenomics
Background:
- Heterologous expression of environmental DNA (eDNA) enables study of previously inaccessible microorganisms.
- Screening microbial extracts has limitations in discovering novel natural products.
- Long-chain N-acyl amino acids are natural products with unknown roles in soil microbial communities.
Purpose of the Study:
- To identify novel natural products from microorganisms using eDNA.
- To characterize the enzymes responsible for producing these compounds.
- To identify a cultured organism capable of producing these molecules for further study.
Main Methods:
- Construction and screening of eDNA cosmid libraries in Escherichia coli.
- Identification of antibacterially active clones.
- Cloning and functional characterization of N-acyl amino acid synthases (NASs).
Main Results:
- Long-chain N-acyltyrosine-producing clones were identified in every eDNA library screened.
- Eleven NAS enzymes were characterized, with ten representing unique sequences.
- A protein from Nitrosomonas europaea, when cloned into E. coli, conferred long-chain N-acyltyrosine production, representing the first functionally characterized NAS from a cultured bacterium.
Conclusions:
- eDNA libraries are a powerful tool for discovering novel natural products like long-chain N-acyltyrosines.
- The identification of a cultured producer (Nitrosomonas europaea) facilitates future research into the ecological roles of these compounds.
- This work expands the known repertoire of natural products and the enzymes that synthesize them.