The CTCF insulator protein forms an unusual DNA structure

The CTCF insulator protein is a highly conserved zinc finger protein that has been implicated in many aspects of gene regulation and nuclear organization. The protein has been hypothesized to organize the human genome by forming DNA loops.In this paper, we report biochemical evidence to support the role for CTCF in forming DNA loops. We have measured DNA bending by CTCF at the chicken HS4 β-globin FII insulator element in vitro and have observed...