ISSN:
1432-1327
Keywords:
Key words Copper
;
metalloregulation
;
Ace1
;
Amt1
;
transcription factor
;
yeast
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The Amt1 and Ace1 transcription factors from Candida glabrata and Saccharomyces cerevisiae are activated by the formation of a tetracopper thiolate cluster resulting in Cu4Zn1Amt1 complexes. An independent Zn module exists within the N-terminal 40 residues of Amt1 and Ace1. There are two conserved histidyl residues within this module. His25 serves as a Zn(II) ligand for the S3N1 site. Thus, Zn(II) ligands are provided by cysteinyl thiolates of Cys11, Cys14, Cys23 and His25. The Zn module is a stably folded domain that binds group IIb metal ions with high affinity. Mutations in Amt1 and Ace1 genes within codons encoding Zn(II) cysteinyl ligands markedly attenuate the ability of Amt1 and Ace1 to mediate Cu-induced expression of metallothionein genes. Thus, the Zn modules in Amt1 and Ace1 are functionally important. A second histidine, His18, is conserved in the Zn module of these metal-activated factors. His18 does not serve a major structural role, but appears important functionally in Ace1 and Amt1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050092
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