Sarah Evert, an IPiB graduate student, will be defending her Ph.D. research on February 5, 2026. Her research in the Raman Lab explored the function of a bacteriophage receptor binding protein.
Evert studied the receptor binding protein of a bacteriophage (a virus that infects bacteria). Receptor binding proteins are essential for phages to recognize and bind to their host bacteria, the first step towards infection. Evert’s research focused on a receptor binding protein with enzymatic activity that both binds to capsulated bacteria and cleaves the capsule (making the bacteria’s membrane accessible).
Using high throughput techniques previously developed in the Raman Lab, Evert produced a library of all possible single point mutations to the binding receptor protein. She then screened the mutations to identify which enhanced and which inhibited the protein’s ability to infect different bacterial hosts.
“One surprising finding is that some phage variants performed better at infecting some bacteria than others,” says Evert. “It’s often thought that there isn’t much discrimination: a protein will perform the same in different bacteria as long as the bacterial capsule type is the same. I found that this isn’t the case. There are mutations to certain positions along the protein that result in the phage performing differently across different hosts with the same capsule type.”
These findings are particularly notable, Evert says, because phages present a promising avenue for treating bacterial infections without the use of antibiotics. Her results point toward possibilities for targeting specific bacteria.
“These capsulated bacteria are already extremely difficult to treat with antibiotics because the capsule forms a protective layer around the bacteria,” explains Evert. “If we have a better understanding of how these proteins function, it lays a groundwork for engineering proteins to target specific bacteria.” Evert hopes the techniques she used to develop the library of mutations will be used by other researchers studying other phages to broaden the field’s understanding of phage function.
With a focus on the basic biological foundations of her research, Evert partnered with labmates Rebecca Back and Silas Miller to create outreach materials for primary school students about phages and bacteria. They created simple, 3D-printed models to illustrate how phages infect bacteria, and presented them at public schools and at the Wisconsin Science Festival.
An active person who loves the outdoors, Evert enjoyed hiking, biking, and running to unwind from her work in the lab, and frequented evening bike outings with the Capital Brewery Bike Club in Middleton. She also competed in the local Ironman race and in the Ironman World Championship in Kona, Hawaii.
Evert, who is a dual citizen of the U.S. and Germany, plans to pursue a career in biotechnology in one of her home countries.
To learn more about Evert’s research, attend her Ph.D. defense, “Deciphering the structural landscape of phage receptor binding proteins” on Thursday, February 5 at 12:30 p.m. CT in Room 175 of Hector F. DeLuca Biochemistry Laboratories Building.
Written by Renata Solan.