Undergraduate Honors Theses

Thesis Defended

Spring 2018

Document Type


Type of Thesis

Departmental Honors


Molecular, Cellular, & Developmental Biology

First Advisor

Dr. Shelley Copley

Second Advisor

Dr. Brian DeDecker

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.


Catalytic promiscuity provides a starting point for the evolution of new enzymes. Taking this concept further, a series of promiscuous enzymes may assemble to form the basis of a new metabolic pathway (termed “serendipitous pathway”) that may emerge and become more efficient in adapting bacterial cells that require it to grow. The Copley lab at the University of Colorado at Boulder has been observing genetic changes that improve growth of Escherichia coli cells that lack the essential gene pdxB. These genetic changes are believed to improve the flux of metabolites through one or more serendipitous pathways that make up for the missing gene. The experiments described in this thesis use gene disruption and growth testing to investigate emerging serendipitous pathways in adapted lineages of ∆pdxB cells. In addition to confirming the emergence of two serendipitous pathways in the adapted cell lineages, I aimed to identify two of the enzymes that catalyze key steps in those pathways, and assess the adaptive benefit that a large deletion provided to one of the adapted lineages.