Z-DNA BINDING PROTEIN AND APPLICATIONS

摘要

Disclosed in the isolation of a 140,000 kDa protein which binds with high affinity to Z-DNA. Z-DNA is defined herein as a non-B-DNA conformer which is stabilized by negative supercoiling. The isolated protein also has a binding site for double-stranded RNA (dsRNA). Peptide sequences from this protein show similarity to double-stranded RNA adenosine deaminase (dsrad), an enzyme which deaminates adenosine in dsRNA to form inosine. Assays for this enzyme confirm that dsrad activity and Z-DNA binding are properties of the same molecule. The coupling of these two activities in a single molecule indicate a novel mechanism of gene regulation which is in part dependent on DNA topology.