Mutations in the bZIP domain of yeast GCN4 that alter DNA-binding specificity

32Citations
Citations of this article
22Readers
Mendeley users who have this article in their library.

Abstract

The bZIP class of eukaryotic transcriptional regulators utilize a distinct structural motif that consists of a leucine zipper that mediates dimerization and an adjacent basic region that directly contacts DNA. Although models of the protein-DNA complex have been proposed, the basis of DNA-binding specificity is essentially unknown. By genetically selecting for derivatives of yeast GCN4 that activate transcription from promoters containing mutant binding sites, we isolate an altered-specificity mutant in which the invariant asparagine in the basic region of bZIP proteins (Asn-235) has been changed to tryptophan. Wild-type GCN4 binds the optimal site (ATGACTCAT) with much higher affinity than the mutant site (7TGACTCAA), whereas the Trp-235 protein binds these sites with similar affinity. Moreover, the Trp-235, Ala-235, and Gln-235 derivatives differ from GCN4 in their strong discrimination against GTGACTCAC. These results suggest a direct interaction between Asn-235 and the ±4 position of the DNA target site and are discussed in terms of the scissors-grip and induced-fork models of bZIP proteins.

Cite

CITATION STYLE

APA

Tzamarias, D., Pu, W. P., & Struhl, K. (1992). Mutations in the bZIP domain of yeast GCN4 that alter DNA-binding specificity. Proceedings of the National Academy of Sciences of the United States of America, 89(6), 2007–2011. https://doi.org/10.1073/pnas.89.6.2007

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free