A One-Step Screening System for Multi-Zinc Finger Proteins Targeting a Long-DNA Sequence

Engineered zinc finger proteins have been widely used for gene editing and transcriptional regulation. Previously, various systems have been utilized in zinc finger screening, but only targeting on sequences no more than 18 bp. Here, we present a novel fast screen method, which is a one-hybrid system based on gp8, a phage-encoded inhibitor of DNA polymerase III. The whole screening process takes 3 days to identify a batch of zinc finger proteins, which could specifically and tightly target on a 300 bp sequence of mouse neurexin1- α promoter. The specificity and efficiency of zinc finger proteins were further validated by in vivo and in vitro assays. Our system provides a high-throughput, rapid and in vivo method for large-scale screening of zinc finger proteins, which is capable to study the protein-DNA interactions.