Artificial Zinc Finger Peptide Containing a Novel His4 Domain (BIOORGANIC CHEMISTRY-Bioactive Chemistry)

Abstract

Zinc finger constitutes one of the most common DNA binding motifs. Although zinc finger proteins consisting of Cys2His2, Cys3His, Cys4, and Cys6 domains are known in nature, a novel His4 zinc finger protein has never been observed. Herein, we have created the first artificial His4-type zinc finger protein (H4Sp1) engineered by Cys to His mutations of the Cys2His2-type zinc finger transcription factor Sp1. The CD features of the single finger H4Sp1f2 and three-finger H4Sp1 clearly demonstrate the folding of the mutant His4 peptides by complexation with Zn(II). The NMR study of Zn(II)-H4Sp1f2 reveals that some distortions of the helical region occur due to Zn(II) coordination. The gel mobility shift assay and DNase I footprinting analysis strongly show the binding of Zn(II)-H4Sp1 to the GC-box site of duplex DNA. The methylation interference pattern of Zn(II)-H4Sp1 binding significantly resembles that of the corresponding C2H2Sp1 binding. The present artificial peptide H4Sp1 is the first example of a zinc finger containing the His4 domain. Of special interest is the fact that the zinc finger domains of H4Sp1 are folded (although not identical to the native structure) and bind DNA similar to wild type C2H2Sp1.