Structure function studies of Sml1, an inhibitor of DNA : synthesis in Saccharomyces cerevisiae

Author

Lezlee Turner Dice

Date of Award

12-2003

Degree Type

Thesis

Degree Name

Master of Science

Major

Biochemistry and Cellular and Molecular Biology

Major Professor

Chris Dealwis

Abstract

Smll is a protein found in yeast that is implicated in regulating ribonucleotide reductase (RNR) and is a member of the Rad53/Mecl cell cycle checkpoint pathway. RNR catalyzes the reduction of ribonucleotides to deoxyribonucleotides. This action is the ratelimiting step of DNA precursor synthesis. 5ml 1 has been shown in other studies to bind to Rnrl, of yeast, thereby inhibiting the reduction activity when DNA synthesis is not required (Zhao, X., Mueller, EGO., and Rothstein, R. ( 1998)). The project presented here utilizes recombinant, truncated mutant forms of Smll and site-directed mutants to investigate the oligomerization and phosphorylation of Smll. Wild type Smll has been truncated by 8, 20, and 38 amino acids, omitting the N-terminal region, which is not thought to interact with Rnrl. These mutants have been used to investigate the oligomeric state of Smll by size-exclusion chromatography and sedimentation equilibrium analytical ultracentrifugation. To characterize phosphorylation of 5ml 1 several serines have been mutated to alanines and a glutamic acid was mutated to a glutamine. The results from these studies have led to the identification of the phosphorylation sites and the key recognition residues of Smll necessary for Dunl kinase activity.

Recommended Citation

Dice, Lezlee Turner, "Structure function studies of Sml1, an inhibitor of DNA : synthesis in Saccharomyces cerevisiae. " Master's Thesis, University of Tennessee, 2003.
https://trace.tennessee.edu/utk_gradthes/5214