[Cloning of A73 gene and its coding sequence analysis].

OBJECTIVE: To clone A73 gene of Epstein-Barr virus (EBV) and examine the variation of its coding sequence.

METHODS: A73 coding sequence (CDS) amplified from 7 patients in nasophryngeal carcinoma (NPC) biopsies by RT-PCR was cloned into pGEM-T-Easy vector to construct the recombinant plasmid, which was subjected to sequence analysis in Gen Bank database using Blast software.

RESULTS: A73 gene from nasophryngeal carcinoma was successfully cloned into pGEM-T Easy vector. A locus with conversion of A-->C in A73 was found at CDS 45 nt, located in the exonVB157154 nt, which did not result in an amino acid replacement, and the variation frequency was 7/7.

CONCLUSION: There is a point mutation in A73 CDS of EBV isolated from NPC tissue, which might produce NPC-associated polymorphism with possible involvement in the composition of some subtype of EB virus.