Kruppel-Like Transcription Factors

Members of the Kruppel-like family of transcription factors have a characteristic DNA-binding domain that consists of three tandem Cys₂His₂ zinc finger motifs at the carboxy-terminus. Kruppel-like transcription factors also contain nuclear localization signals immediately adjacent to or within the zinc finger motifs. Each zinc finger is highly conserved and has a consensus sequence [C-X_2-5-C-X₃-(F/Y)-X₅-psi-X₂-H-X_3-5-H (psi represents a hydrophobic residue)]. Additionally, the linker regions separating each zinc finger are highly conserved, consist of seven amino acids, and share a consensus sequence [TGE(R/K)(P/K/R)(F/Y)X]. DNA sequence specificity varies within the Kruppel-like transcription factor family. Kruppel-like transcription factors are involved in growth-regulatory and developmental processes in a large number of tissues.