Tafuri S R, Wolffe A P
Laboratory of Molecular Embryology, NICHD, NIH, Bethesda, MD 20892.
New Biol. 1992 Apr;4(4):349-59.
The Y box factors bind to a specific DNA sequence (the Y box, containing a reverse CCAAT element) and have been implicated in the regulation of transcription. We have used deletion mutagenesis to define the protein domains of two Xenopus Y box factors, FRG Y1 and FRG Y2, that are essential for DNA binding, multimerization, and transcription. A domain of the Y box factors homologous to an Escherichia coli cold shock protein is required for DNA binding. Both the E. coli protein and the Y box factors recognize DNA sequences with similar selectivity. The conserved region between these proteins does not contain any previously defined DNA-binding motifs. The hydrophilic C-terminal tail of the proteins contributes to the assembly of nucleoprotein complexes. This region contains an unusual pattern of basic and acidic amino acids and represents a new type of domain mediating protein-protein interactions in transcription factors. Both the DNA-binding and the multimerization domains are important for stimulating transcription from the Xenopus hsp70 promoter in vitro.
Y盒因子与特定的DNA序列（Y盒，含有反向CCAAT元件）结合，并参与转录调控。我们利用缺失诱变来确定两种非洲爪蟾Y盒因子FRG Y1和FRG Y2的蛋白质结构域，这些结构域对于DNA结合、多聚化和转录至关重要。Y盒因子中与大肠杆菌冷休克蛋白同源的结构域是DNA结合所必需的。大肠杆菌蛋白和Y盒因子识别具有相似选择性的DNA序列。这些蛋白之间的保守区域不包含任何先前定义的DNA结合基序。蛋白质的亲水性C末端尾巴有助于核蛋白复合物的组装。该区域包含一种不寻常的碱性和酸性氨基酸模式，代表了一种介导转录因子中蛋白质-蛋白质相互作用的新型结构域。DNA结合结构域和多聚化结构域对于在体外刺激非洲爪蟾hsp70启动子的转录都很重要。
