Binding of the Zα from Carassius auratus PKR-like to d(GC)₁₃ Plasmid and Its Analysis of Adaptive Evolution

Abstract: The Zα domain from several proteins of species could recognize and bind to Z-DNA. The structure of Zα domain was conserved and diverged from a common ancestor. Zα was highly functional conserved during the evolvement by adaptive evolutional analysis. Therefore， the Zα was not in the positive selection pressure. The peptides， CaPZα， CaPN38A and CaPW60A were expressed by a prokaryotic expression system and purified by affinity chromatography. CaPZα has the ability to bind to pMD18-T/(GC)₁₃ instead of pMD18-T by the gel band shift assay. The binding of the CaPZα to (GC)₁₃ is weaker than ADAR1 Zα， because the CaPZα1 or CaPZα2 can not bind to pMD18-T/(GC)₁₃. Though the function of the Zα doesn't vary， these are different. The negative supercoil and d(GC)_n maybe the necessary factors for DNA to form Z-DNA conformation. The site directed mutagenesis proved that the two amino acid sites， 38N and 60W， are important for CaPZα binding to DNA.
    

CSTR: 32200.14.cjcb.2008.04.0017