Autoactivation by a Candida glabrata copper metalloregulatory transcription factor requires critical minor groove interactions.


Journal Article

Rapid transcriptional autoactivation of the Candida glabrata AMT1 copper metalloregulatory transcription factor gene is essential for survival in the presence of high extracellular copper concentrations. Analysis of the interactions between purified recombinant AMT1 protein and the AMT1 promoter metal regulatory element was carried out by a combination of missing-nucleoside analysis, ethylation interference, site-directed mutagenesis, and quantitative in vitro DNA binding studies. The results of these experiments demonstrate that monomeric AMT1 binds the metal regulatory element with very high affinity and utilizes critical contacts in both the major and minor grooves. A single adenosine residue in the minor groove, conserved in all known yeast Cu metalloregulatory transcription factor DNA binding sites, plays a critical role in both AMT1 DNA binding in vitro and Cu-responsive AMT1 gene transcription in vivo. Furthermore, a mutation in the AMT1 Cu-activated DNA binding domain which converts a single arginine, found in a conserved minor groove binding domain, to lysine markedly reduces AMT1 DNA binding affinity in vitro and results in a severe defect in the ability of C. glabrata cells to mount a protective response against Cu toxicity.

Full Text

Duke Authors

Cited Authors

  • Koch, KA; Thiele, DJ

Published Date

  • February 1996

Published In

Volume / Issue

  • 16 / 2

Start / End Page

  • 724 - 734

PubMed ID

  • 8552101

Pubmed Central ID

  • 8552101

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/mcb.16.2.724


  • eng

Conference Location

  • United States