Hu J C, O'Shea E K, Kim P S, Sauer R T
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Science. 1990 Dec 7;250(4986):1400-3. doi: 10.1126/science.2147779.
A genetic system was developed in Escherichia coli to study leucine zippers with the amino-terminal domain of bacteriophage lambda repressor as a reporter for dimerization. This system was used to analyze the importance of the amino acid side chains at eight positions that form the hydrophobic interface of the leucine zipper dimer from the yeast transcriptional activator, GCN4. When single amino acid substitutions were analyzed, most functional variants contained hydrophobic residues at the dimer interface, while most nonfunctional sequence variants contained strongly polar or helix-breaking residues. In multiple randomization experiments, however, many combinations of hydrophobic residues were found to be nonfunctional, and leucines in the heptad repeat were shown to have a special function in leucine zipper dimerization.
在大肠杆菌中开发了一种遗传系统，以噬菌体λ阻遏物的氨基末端结构域作为二聚化的报告基因来研究亮氨酸拉链。该系统用于分析来自酵母转录激活因子GCN4的亮氨酸拉链二聚体疏水界面八个位置上氨基酸侧链的重要性。当分析单个氨基酸取代时，大多数功能变体在二聚体界面含有疏水残基，而大多数无功能的序列变体含有强极性或破坏螺旋的残基。然而，在多个随机化实验中，发现许多疏水残基组合无功能，并且七肽重复中的亮氨酸在亮氨酸拉链二聚化中具有特殊功能。
