RESUMO
The CTCF-like protein, CTCFL, is a DNA-binding factor that regulates the transcriptional program of mammalian male germ cells. CTCFL consists of eleven zinc fingers flanked by polypeptides of unknown structure and function. We determined that the C-terminal fragment predominantly consists of extended and unordered content. Computational analysis predicts that the N-terminal segment is also disordered. The molecular architecture of CTCFL may then be similar to that of its paralog, the CCCTC-binding factor, CTCF. We speculate that sequence divergence in the unstructured terminal segments results in differential recruitment of cofactors, perhaps defining the functional distinction between CTCF in somatic cells and CTCFL in the male germ line.
Assuntos
Proteínas de Ligação a DNA/química , Dedos de Zinco , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/isolamento & purificação , Humanos , Masculino , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
The human CCCTC-binding factor, CTCF, organizes and regulates transcription of the genome by colocalizing distant DNA elements on the same and even different chromosomes. This protein consists of 11 zinc fingers flanked by polypeptide segments of unknown structure and function. We purified recombinant terminal fragments and observed that both are extended, monomeric, and predominantly consist of unordered content. We thus speculate that the role of the terminal extensions, and perhaps all of CTCF, is to act as a scaffold for the assembly of other proteins on a specific binding site.