CAREER: On The Workings of DNA Mismatch Repair Proteins

Wesleyan University, Middletown CT

Investigators

Abstract

The DNA mismatch repair system maintains the integrity of the genome by locating and correcting errors in DNA, and preventing recombination between non-identical DNA sequences. Thus, it plays a critical role in DNA metabolism. Mismatch repair initiates with the MutS protein (or MutS homologues) recognizing a base pairing defect in the double helix, followed by stimulation of nuclease activities that result in limited excision of the error-containing strand, and re-synthesis of correct DNA by replication proteins. Mismatch repair proteins have been the focus of intense study over the past several years; however, in many cases, the mechanistic basis of their actions is not clearly understood. To understand the workings of these proteins, the research project will address: (a) how MutS protein specifically recognizes mis-paired DNA from the vast excess of normal duplex DNA in the cell; (b) how MutS protein uses ATP to set in motion the events leading to DNA repair; and (c) events occurring in the repair pathway immediately following mismatch recognition and the role of ATP at this stage. The primary approach in these studies will be the application of rapid kinetic techniques to observe reactions in real time and determine the kinetic and thermodynamic parameters governing mismatch repair protein actions. The research project will be coupled with initiatives aimed at improving understanding and communication of molecular biology and biochemistry among students of science and other disciplines. Educational activities will include development of courses on science documentary filmmaking as well as science writing, introduction of outreach activities in science courses, and increasing opportunities for students to engage in individual research. Thus, in addition to improving understanding of a key cellular DNA repair pathway, the project aims to further science literacy in the student community, within and beyond the university.