Cloning, Sequencing and Structural Analysis of the Protein Kinase Gene of a Wild Chinese Pseudorabies Virus Strain

The protein kinase gene in the unique short region of the wild Chinese pseudorabies virus Hubei strain was amplified by polymerase chain reaction(PCR). The PCR product was ligated to pUC 19 plasmid vector, and its nucleotide sequence was determined by the dideoxy mediated chain termination method. An analysis of the nucleotide sequence and its deduced amino acid sequence were performed with computer programs. The results revealed that the region of DNA sequenced is 1 312 base pairs and has the content of G+C 67%, the region has the potential to encode a protein of 334 amino acids. The PK gene of PRV HB strain shares highly conserved nucleotide with PRV NIA 3 strain and Ka strain, and is homology to gene Us3 of herpes simplex virus Type 1(HSV 1) and gene 66 of varicella zoster virus(VZV). The homology of the nucleotide sequence of PRV HB strain with PRV NIA 3 strain, Ka strain, HSV 1, VZV is 98.7%、97.5%、50.7% and 42.0%, respectively; and the homology of deduced amino acids among them is 98.2%、95.8%、37.7% and 37.2%, respectively. The amino acids of PRV PK contain most of the conserved motifs of a eukaryotic serine/ threonine protein kinase. These results might be contributive to the study of the molecular mechanism of PRV virulence and the development of an genetically engineered PK deleted PRV vaccine.