Electronic Thesis and Dissertation Repository


Master of Science




Christopher Brandl


Spt7 is a 1,332 residue protein critical for maintaining structural integrity of the SAGA complex. I demonstrated that the extreme N-terminus of Spt7 plays an important role in SAGA function. Deletion of the first 73 (Spt773-1332) and 121 (Spt7121-1332) N- terminal residues resulted in slow growth, decreased transcriptional activation at PHO5 and INO1, and a partial decrease in acetylation at lysine 18 of histone H3 at PHO5. The Spt7121-1332 mutant did not affect Spt7’s association with Gcn5 or Tra1, or its localization within the cell. Mutation of the first four positively charged residues to glutamine severely reduced PtdInsP binding by Spt7. I mapped this binding to the first two positively charged residues, arginine 4 (R4) and lysine 8 (K8). Overall, the N-terminus of Spt7 is important for the function of SAGA, likely in part through its ability to bind PtdInsPs.