EUKARYOTIC GENE REGULATION AND FUNCTION--THE METALLOTHIONEIN SYSTEM

铜离子通过改变酵母金属硫蛋白基因的转录水平诱导其表达 ACE 1转录因子的构象和DNA结合活性。我们 已经提出ACE 1的氨基末端结构域形成多核的 Cu（I）-S簇，或“铜拳”，将蛋白质组织成一个 特异性DNA结合因子为了支持这个模型，我们已经证明， ACE 1协同结合Cu（I），即Cu结合半胱氨酸残基和 DNA结合碱性残基在单个结构域内相互交叉，并且 纯化的ACE 1肽是发光的。体外转录 系统响应ACE 1已经开发，和遗传搜索 另外的金属硫蛋白基因转录因子已经启动。

Cu ions induce yeast metallothionein gene transcription by altering the conformation and DNA binding activity of the ACE1 transcription factor. We have proposed that the amino-terminal domain of ACE1 forms a polynuclear Cu(I)-S cluster, or "copper fist", which organizes the protein into a specific DNA binding factor. In support of this model, we have shown that ACE1 binds Cu(I) cooperatively, that the Cu-binding cysteine residues and DNA-binding basic residues are interdigitated within a single domain, and that a purified ACE1 peptide is luminescent. An in vitro transcription system responsive to ACE1 has been developed, and a genetic search for additional metallothionein gene transcription factors has been initiated.