The Affinity Of The APKR-like Zα Domain With Nucleic Acids

The CaPKR-like was the first identified fish gene which is most similar tomammalian PKR. The protein encoded by the gene possesses a conserved C-terminalcatalytic domain. Instead of the dsRNA-binding domains (dsRBD) which isconserved in mammalian PKR, there are two putative Z-DNA binding domains (Zα1and Zα2) within its N-terminus. The Zαdomain was first identified in ADAR1(double-stranded RNA adenosine deaminase). So CaPKR-like is belong to Zαproteinfamily.Here, the cDNA of Zα1, Zα2 and Zα1Zα2 were cloned from SMART-cDNA library to thevector. Three kinds of cDNA of Zα1, Zα2 and Zα1Zα2 were expressed in prokaryotic system. Thefusion Zα_PKR-like peptides were purified by affinity chromatography. Gel retardarce assay was beused to analyze the affinity, of Zα_PKR-like with Poly I: C, salomo testes DNA. recombined d(CG)₁₃vector and d(CG)₁₃, respectively. The results show that neither P_Zα1 nor P_Zα2 could bind to Poly I: C,salomo testes DNA and d(CG)₁₃, but the whole structure P_Zα1Zα2 could bind to Poly I: C, salomotestes DNA, recombined d(CG)₁₃ vector and d(CG)₁₃ sequence strongly.