Graduation Year


Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts



Reader 1

Bethany Caulkins

Reader 2

Mary Hatcher-Skeers

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The coenzyme pyridoxal-5’-phosphate (PLP) is prolific, found in a widespread variety of enzymes that produce and manipulate amino acids. One particularly important example of such a PLP enzyme, tryptophan synthase (TS), catalyzes the final two steps in the L-tryptophan biosynthesis pathway.

Due to the complexity of the TS complex, individual residue mutations have the potential to have large effects on the affinity and catalytic efficiency of the enzyme, among other attributes. This thesis will, using the interactive visualization program UCSF Chimera, explore the interactions between two important PLP functional groups– the pyridine ring nitrogen and C4’ aldehyde–and the corresponding bound residues located on the TS β-site. In addition to wildtype TS, this study will also analyze these counterpart structures in the crystallographic structures of the following tryptophan synthase mutants: β110V, βQ114N, βK87T, βK167T, βD305A, and αT183V.

While general consensus is that mutations, specifically β-site mutations, compromise the ability of TS to allosterically regulate itself and smoothly catalyze the final step in L-tryptophan biosynthesis, this thesis is intended to explore and understand the structural perturbations that drive the changed capabilities of these mutated TS species.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.