Krüppel-associated boxes are potent transcriptional repression domains.

摘要: Abstract The Kruppel-associated box (KRAB) is a highly conserved, 75-aa region containing two predicted amphipathic alpha-helices. The KRAB domain present in the amino-terminal regions of more than one-third all Kruppel-class Cys2His2 zinc finger proteins and conserved from yeast to man; however, its function unknown. Here it shown that functions as DNA binding-dependent transcriptional repressor when fused heterologous DNA-binding GAL4 protein. A 45-aa segment one helices was necessary sufficient for repression. Amino acid substitutions helix abolished repression function. These results assign function, repression, define minimal which may aid identifying mechanisms