FUNCTIONAL DISSECTION AND SEQUENCE OF YEAST HAP1 ACTIVATOR
FUNCTIONAL DISSECTION AND SEQUENCE OF YEAST HAP1 ACTIVATOR
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DOI：
10.1016/0092-8674(89)90903-3
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发表时间：
1989-01-27
期刊：
影响因子：
64.5
通讯作者：
GUARENTE, L
中科院分区：
文献类型：
--
作者：
PFEIFER, K;KIM, KS;GUARENTE, L
我们提出了DNA序列和1483残留酵母激活物HAP1的功能解剖。突出的结果是，首先，单个DNA结合域（1-148）指定与不同序列的两个靶点UAS1和CYC7结合。这个结构域包含一个富含半胱氨酸的锌指，两个半胱氨酸中的任何一个突变都可以消除与这两个位点的结合。其次，存在特异性消除与UAS1或CYC7结合的突变。这些变化要么发生在紧邻手指的氨基末端的残基上，要么发生在紧邻手指的羧基序列上。因此，手指的基部和羧基侧翼残基都参与了特定的DNA结合。第三，在没有诱导剂的情况下，一个独特的区域（残基245-445）通过掩盖DNA结合域介导血红素诱导；血红素可能通过与该区域的金属结合特征的重复序列相互作用来抵消这种屏蔽。而445 - 1308之间的序列没有明显的功能，一个高酸性的羧基末端介导HAP1的转录激活。
We present the DNA sequence and a functional dissection of the 1483 residue yeast activator HAP1. Salient results are, first, a single DNA binding domain (1-148) specifies binding to the two target sites of different sequence, UAS1 and CYC7. This domain contains a cysteine-rich zinc finger, and mutation of either of two cysteines abolishes binding to both sites. Second, mutations that specifically abolish binding to UAS1 or to CYC7 exist. These changes lie either in the residue immediately amino-terminal to the finger or in sequences carboxyl to the finger. Thus, both the base of the finger and carboxyl flanking residues are involved in specific DNA binding. Third, a distinct region (residues 245-445) mediates heme induction by masking the DNA binding domain in the absence of inducer; heme counteracts this masking, perhaps by interacting with a repeat sequence of metal binding character in this region. While sequences between 445 and 1308 have no obvious function, a highly acidic carboxyl terminus mediates transcriptional activation by HAP1.