Thompson C C, Brown T A, McKnight S L
Howard Hughes Research Laboratories, Carnegie Institution of Washington, Department of Embryology, Baltimore, MD 21210.
Science. 1991 Aug 16;253(5021):762-8. doi: 10.1126/science.1876833.
Analysis of the heteromeric DNA binding protein GABP has revealed the interaction of two distinct peptide sequence motifs normally associated with proteins located in different cellular compartments. The alpha subunit of GABP contains an 85-amino acid segment related to the Ets family of DNA binding proteins. The ETS domain of GABP alpha facilitates weak binding to DNA and, together with an adjacent segment of 37 amino acids, mediates stable interaction with GABP beta. The beta subunit of GABP contains four imperfect repeats of a sequence present in several transmembrane proteins including the product of the Notch gene of Drosophila melanogaster. These amino-terminal repeats of GABP beta mediate stable interaction with GABP alpha and, when complexed with GABP alpha, directly contact DNA. These observations provide evidence for a distinct biochemical role for the 33-amino acid repeats, and suggest that they may serve as a module for the generation of specific dimerization interfaces.
对异源二聚体DNA结合蛋白GABP的分析揭示了两个不同的肽序列基序之间的相互作用，这两个基序通常与位于不同细胞区室的蛋白质相关。GABP的α亚基包含一个与DNA结合蛋白的Ets家族相关的85个氨基酸的片段。GABPα的ETS结构域促进与DNA的弱结合，并与相邻的37个氨基酸片段一起介导与GABPβ的稳定相互作用。GABP的β亚基包含几个跨膜蛋白（包括果蝇Notch基因的产物）中存在的序列的四个不完全重复。GABPβ的这些氨基末端重复序列介导与GABPα的稳定相互作用，并且当与GABPα复合时，直接接触DNA。这些观察结果为33个氨基酸重复序列的独特生化作用提供了证据，并表明它们可能作为产生特定二聚化界面的模块。
