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Keelie Butler

Posted on October 6, 2021

Keelie Butler


Date - October 6, 2021
1:00 pm - 2:00 pm


Ph.D. Thesis Defense – 751
Title: “The Biosynthesis of Colibactin”
Advisor – Dr. Jonathan Chekan


Decades of research has been devoted to understanding the human microbiome and how it correlates to human health. Based on the correlative data, many research groups have analyzed the possibility of causal relationships of bacteria in the human microbiome and human health. Among the results of this research, a secondary metabolite, colibactin, produced by Escherichia coli has been shown to have genotoxic capabilities, and has been positively correlated to colorectal cancer. Using bioinformatic techniques, the Oswald group was able to isolate the genome cluster responsible for producing colibactin. Due to colibactin’s proposed reactivity, isolating the mature compound was not able to be done within a laboratory setting. With the biosynthetic gene cluster identified, however, the Herzon and Crawford groups were able to analyze the biosynthesis and elucidate the structure of colibactin, which could lead to mechanistic studies of colibactin as a causal agent for colorectal cancer.