PROPERTIES OF BGP1, A POLY(DG)-BINDING PROTEIN FROM CHICKEN ERYTHROCYTES
PROPERTIES OF BGP1, A POLY(DG)-BINDING PROTEIN FROM CHICKEN ERYTHROCYTES
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DOI：
10.1093/nar/18.17.5119
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发表时间：
1990-09-11
影响因子：
14.9
通讯作者：
FELSENFELD, G
中科院分区：
文献类型：
--
作者：
CLARK, SP;LEWIS, CD;FELSENFELD, G
鸡βA-珠蛋白基因在其5''启动子附近含有16个碱基对长的(dG)-均聚物序列。从鸡红细胞中分离出来的 66 kD 蛋白 BGP1（β 珠蛋白蛋白 1）已被证明与该序列特异性结合。我们描述了 BGP1 的进一步纯化，测量其对 βA-珠蛋白启动子结合位点的亲和力，并分析其结合特性。最小结合序列是七个 dG 残基；甲基化干扰研究表明，这些残基中的每一个都与 BGP1 接触。使用 (dG) .cntdot 进行结合竞争实验。不同长度的(dC)寡聚物也与作为最小识别序列的(dG)7一致。所有数据都可以通过一个模型来解释，其中 BGP1 与任何连续的七个 (dG) 残基集结合，因此与 (dG)n 结合的有效常数与 n 减 6 成正比。这种行为可能是与重复序列特异性结合的蛋白质的典型行为。
The chicken .beta.A-globin gene contains in the neighborhood of its 5'' promoter a (dG)-homopolymer sequence 16 base pairs long. The 66 kD protein BGP1 (beta globin protein 1), isolated from chicken erythrocytes, has been shown to bind specifically to this sequence. We describe further purification of BGP1, measure its affinity for the .beta.A-globin promoter binding site, and analyze its binding properties. The minimal binding sequence is seven dG residues; methylation interference studies show that each of these residues contacts BGP1. Binding competition experiments employing (dG) .cntdot. (dC) oligomers of varying lengths also are consistent with (dG)7 as a minimum recognition sequence. All of the data can be explained by a model in which BGP1 binds to any contiguous set of seven (dG) residues, so that the effective constant for binding to (dG)n is proportional to n minus 6. This behavior may be typical of proteins that bind specifically to repeated sequences.