A.J. Courey, D.A. Holtzman, S.P. Jackson, R. Tjian, "Synergistic activation by the glutamine-rich domains of human transcription factor Sp1," Cell, 59:827-36, 1989.
Albert J. Courey20(Department of Chemistry and Biochemistry, University of California, Los Angeles): "The biochemical mechanism by which distal promoter elements can stimulate transcriptional initiation at a site located many thousands of base pairs away has been a mystery since the discovery of this phenomenon in the early 1980s.
"In this paper, we show that distantly bound molecules of the human transcription factor Sp1 interact with more proximally bound Sp1 to synergistically activate transcription. We provide evidence suggesting that these synergistic interactions involve direct protein-protein contacts between molecules of Sp1.
"Recently, other labs have followed up on these observations to demonstrate, through the use of electron microscopy, that distally and proximally bound Sp1 molecules do indeed contact one another, thereby forming a loop of DNA several kilobases in...