Susan Zhang

Degree Type

Honors Capstone Project

Date of Submission

Spring 5-1-2013

Capstone Advisor

Assistant Professor James L. Hougland

Honors Reader

Assistant Professor Heather Coleman

Capstone Major


Capstone College

Arts and Science

Audio/Visual Component


Capstone Prize Winner


Won Capstone Funding


Honors Categories

Sciences and Engineering

Subject Categories

Biochemistry | Biochemistry, Biophysics, and Structural Biology


Post-translational modifications play an essential role in regulating protein structure and function. Enzymes catalyzing these modifications must often recognize and modify multiple substrate proteins from among a plethora of non-substrates with similar structures and amino acid sequences. For example, protein farnesyltransferase (FTase) catalyzes the addition of an isoprenoid group to a cysteine near the C-terminus of a substrate protein and is proposed to modify a pool of substrates numbering more than one hundred. We seek to understand the interactions in the FTase active site that engender substrate selectivity. By mutating two residues within FTase, we have developed FTase variants with expanded substrate selectivity. The alteration in substrate selectivity observed in our variants suggests that FTase selectivity may depend on a small number of “tunable” active site contacts. Our work provides insight into how this multispecific enzyme recognizes its pool of substrates and will also aid in identifying additional FTase substrates.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Included in

Biochemistry Commons



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