ABSTRACT
Objective To investigate the polymorphism of human cytomegalovius UL143 gene of low passage clinical isolates in Guangzhou,China.Method PCR was performed to amplify the entire HCMV ULl43 gene region of 3 clinical isolates,which had been proven by multiplex PCR.The amplification products were cloned into pMD18-T-Vector and subjected to sequencing.The result of DNA sequences were analyzed together with the one of published homologous sequences in GenBank from 14 clinical isolates.Result There were several stop codons in UL143 gene due to a base deletion in open reading frame (ORF) of D3 isolate,which could lead to produce non-functional protein.UL143 ORF of Toledo isolate consisted of 279 nueleotides,encoding a protein with 92 amino acids.UL143 ORFs of other isolates consisted of 252 nueleotides,encoding a protein with 83 amino acids.The DNA sequences were quite conserved and all the variations were base substitution.The amino acid sequences of different isolates were highly conserved.with variation of 1.2%-2.4%.There were no additional or deleted sites of post translational modification of UL143 protein in all clinical isolates except Toledo isolate.There were some differences in the secondary structure among different isolates.The isoelectric point of UL143 protein of all clinical isolates except Toledo isolate was 8.75.Conclusion All DNA and deduced amino acid sequences of UL143 gene shared great similarity among HCMV clinical strains regardless of their polymorphism.