Probing the emergence of novel protopathways from underground metabolism

Protein enzymes catalyze almost every metabolic reaction in all living organisms. Most enzymes are specialized for certain tasks, but most have side activities termed “promiscuous” activities. Promiscuous protein enzyme activities are typically inefficient but are still a million-fold better than chemical activities without protein. Consequently, promiscuous activities provide a good starting point for evolution of efficient new enzymes, both in nature and in the laboratory. Promiscuous enzymes can also be combined to generate novel metabolic pathways. This project will focus on the evolution of novel metabolic pathways, focusing on how individual mutations allow the assembly and optimization of a novel pathway and on how the collections of promiscuous enzymes in different bacteria lead to different pathways. The results from this research could provide insight on ways to develop novel pathways for biodegradation and synthesis of pharmaceuticals, biofuels, and chemicals. The educational activities involve training of undergraduates and graduate students and outreach to high school and middle school students. This work will address NSF priorities in Biotechnology, as well as Advanced Materials and Manufacturing. Since the dawn of life, evolution of novel metabolic pathways has enabled new strategies for exploiting environmental resources and manipulating competing and cooperating organisms. Bioinformatic evidence suggests that organisms evolve novel metabolic pathways by bringing together existing enzymes with promiscuous side activities into new combinations. This project will use adaptive laboratory evolution coupled with genetic, "omics", and biochemical approaches to address the following questions. What promiscuous enzymes were available in the organism in which a new pathway evolved? How do mutations elevate flux through an emerging pathway? Why did one pathway emerge rather than other possibilities? Why do some bacteria evolve the same pathway via different mutations while other bacteria evolve different protopathways? This work will provide an unprecedented look at the early stages of the evolution of novel metabolic pathways and how the resources in different genomes influence the outcome when a new metabolic pathway is needed. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2548055 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Shelley Copley | Institution: University of Colorado at Boulder, BOULDER, CO | Award Amount: $1,058,870 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2548055 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2548055.html