Date of Award

Spring 2001

Document Type

Restricted Thesis

Terms of Use

© 2001 Beth E. Williams. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts



First Advisor

Elizabeth Ann Vallen


The SID2 gene of Saccharomyces cerevisiae plays a currently unspecified role in DNA replication and/or repair. This study examined the intracellular localization of Sid2p as well as potential genetic interactions between SID2 and DNA repair and checkpoint genes. The viability of strains carrying an inducible SID2 allele and a deletion of either rad9 or rad52 was assessed. It was found that the combination of down-regulated SID2 expression and rad9∆ resulted in a slight decrease in viability, while over-expression of SID2 rescued the slight growth defect in rad52∆. Sid2p localization was studied through a one-hybrid genetic assay. The results indicate that Sid2p enters the nucleus, but at a lower level than a control protein carrying the SV40 large T-antigen "classical" NLS. This may reflect that Sid2p's NLS is less efficient at promoting import or that Sid2p's localization is regulated, perhaps with respect to the cell cycle. The observed genetic interactions and the apparent nuclear localization of Sid2p are both consistent with SID2's proposed role(s) in DNA replication and/or repair.