Related Experiment Video
Updated: Jun 16, 2026
09:08
From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028
Published on: January 13, 2017
Synthetic chain terminators off-load intermediates from a type I polyketide synthase.
Manuela Tosin1, Lorena Betancor, Elaine Stephens
1Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, UK. mt406@cam.ac.uk
Chembiochem : a European Journal of Chemical Biology
|February 6, 2010
Summary
Researchers developed nonhydrolyzable mimics to trap biosynthetic intermediates from polyketide synthases. This method allows for the isolation and analysis of crucial intermediates in drug discovery.
Area of Science:
- Biochemistry
- Synthetic Biology
- Drug Discovery
Background:
- Modular biocatalysis generates numerous bioactive products, making it a key area for drug discovery.
- A significant challenge in studying these pathways is isolating and analyzing biosynthetic intermediates.
- Type I polyketide synthases (PKS) are complex enzymes responsible for producing a wide range of natural products.
Purpose of the Study:
- To develop a method for trapping and isolating biosynthetic intermediates from type I PKS.
- To create nonhydrolyzable mimics of natural (methyl)malonyl extender units.
- To utilize these mimics as probes for understanding polyketide biosynthesis.
Main Methods:
- Synthesized nonhydrolyzable pantetheine and N-acetyl cysteamine mimics.
- Used these mimics as competitive substrates with an in vitro reconstituted 6-deoxyerythronolide B synthase 3 (DEBS3).
- Extracted and characterized trapped diketide and triketide intermediates using LC-HR-ESI-MS.
Main Results:
- Successfully trapped and off-loaded diketide and triketide intermediates from DEBS3.
- The trapped intermediates are the first of their kind to be isolated and characterized.
- Demonstrated the utility of small-molecule chain terminators as probes for biosynthetic processes.
Conclusions:
- Nonhydrolyzable mimics serve as effective chain terminators for trapping polyketide intermediates.
- This approach provides a novel strategy for analyzing biosynthetic intermediates in modular biocatalysis.
- The findings facilitate further drug discovery efforts by enabling better understanding of PKS pathways.
More Related Videos
Related Concept Videos
01:09Radical Chain-Growth Polymerization: Mechanism
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into the...
01:28ATP and Macromolecule Synthesis
Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, nitrogen, and other minor elements. There are four major biological macromolecule classes: carbohydrates, lipids, proteins, and nucleic acids.
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
00:57Cationic Chain-Growth Polymerization: Mechanism
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
02:42Transcription Attenuation in Prokaryotes
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
01:04Anionic Chain-Growth Polymerization: Mechanism
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael acceptor.
01:10Radical Chain-Growth Polymerization: Overview
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...