Enzyme promiscuity under direction
Researchers with the FUNCEVODUPLIGENES (Probing the evolution of promiscuity and functional diversification among ancient gene duplicates) project have pursued the reasons for genetic differences between duplicates. Success in this research area will further knowledge on protein evolution. Other benefits include directed use of promiscuous enzymes where an enzyme has a second function that can be used in biotech. Moreover, more accurate genetic engineering of industrial enzymes and accurate predictions regarding evolution of antibiotic resistance on introduction of new antimicrobials will be possible. The scientists cultured mutants of Escherichia coli (E. coli) to investigate functional diversification of flavoprotein disulphide reductases (FDRs). However, after confirmation of inefficient protein production of FDRs in these mutants, the researchers manipulated the ribosome binding site that drives translation of these FDRs. Using a yellow fluorescent protein as a reporter, the researchers developed a high throughput method to characterise the translation potential of large RBS libraries, as many as a quarter of a million variants. The next step was to identify those that conferred efficient protein expression. For future research, replacing the current RBS of FDRs with these efficient variants would then test their capacity to boost FDR expression in the bacterium. Knowledge on function change for gene sequences can be applied in the use of promiscuous enzymes in bioindustrial sectors such as enzymology, chemical biology and cutting-edge directed evolution techniques.
Keywords
Enzyme promiscuity, protein evolution, industrial enzymes, antibiotic resistance