Propagation of Recombinant Genes through Complex Microbiomes with Synthetic Mini-RP4 Plasmid Vectors

Area of Science:

• Microbiology
• Molecular Biology
• Synthetic Biology

Background:

• The Gram-negative plasmid RP4 possesses a promiscuous conjugation system.
• Efficient gene transfer is crucial for manipulating microbial communities.

Purpose of the Study:

• To reassemble the RP4 conjugation machinery into a minimized, highly transmissible vector.
• To create a tool for propagating genetically encoded traits in diverse microbial communities.

Main Methods:

• Excised and minimized RP4 transfer determinants (tra, mob genes, oriT) into a streamlined DNA segment.
• Utilized an autoselective replicon to create the pMATING vector series.
• Inserted a Green Fluorescent Protein (GFP) reporter gene to track transfer.

Main Results:

• The pMATING vectors demonstrated self-transfer to diverse prokaryotic and eukaryotic recipients.
• Effective and functional transfer of recombinant plasmids to various hosts was confirmed.
• Type VI secretion systems were identified as a barrier limiting interspecies DNA transfer.

Conclusions:

• The developed pMATING system is a rational, rationally designed conjugal delivery device for gene propagation.
• This hyperpromiscuous gene transfer system can be a valuable asset for spreading beneficial traits in environmental microbiomes.
• Understanding barriers like type VI secretion systems is key to optimizing gene transfer efficiency.