Distinct Regions of Sp1 Modulate DNA Binding and Transcriptional Activation

作者：James T. Kadonaga, Albert J. Courey, Joseph Ladika, Robert Tjian · 发表于：Science · 年份：1988 · DOI：10.1126/science.3059495 · 被引用次数：379 · 研究领域：RNA and protein synthesis mechanisms、Genomics and Chromatin Dynamics、Bacterial Genetics and Biotechnology

Sp1 is a sequence-specific DNA binding protein that activates RNA polymerase II transcription from promoters that contain properly positioned GC boxes. A series of deletion mutants of Sp1 were expressed in Escherichia coli and used to identify separate regions of the protein that are important for three different biochemical activities. The sequence-specificity of DNA binding was conferred by Zn(II) fingers, whereas a different region of Sp1 appeared to regulate the affinity of DNA binding. The E. coli-synthesized Sp1 was able to stimulate initiation of RNA synthesis in vitro, and at least two distinct segments of the protein contributed to its transcriptional activity.