Type III polyketide synthases in natural product biosynthesis

Area of Science:

• Biochemistry and Molecular Biology
• Natural Product Synthesis
• Enzymology

Background:

• Polyketides are diverse, biologically active natural compounds.
• Polyketide synthases (PKSs) synthesize polyketides from acyl-CoA substrates.
• PKSs are classified into three main types: I, II, and III.

Purpose of the Study:

• To review recent research on type III polyketide synthases (PKSs).
• To detail the catalytic functions of type III PKSs across different organisms.
• To explore the implications of type III PKS discovery in fungi for secondary metabolism.

Main Methods:

• Review of recent scientific literature on type III PKSs.
• Analysis of catalytic functions based on existing studies.
• Examination of findings from fungal genome sequencing and biochemical studies.

Main Results:

• Type III PKSs are found in plants (e.g., chalcone synthase), bacteria (five groups, notably in Streptomyces), and newly identified in fungi.
• Detailed catalytic functions of these enzymes are described.
• Fungal type III PKSs offer new avenues for studying secondary metabolism and creating novel compounds.

Conclusions:

• The discovery of type III PKSs in fungi broadens their known phylogenetic distribution.
• Type III PKSs are versatile tools for synthesizing novel molecules via precursor-directed and structure-based mutagenesis.
• Further research into fungal type III PKSs holds significant potential for natural product discovery.