Analysis and expression of tumor necrosis factor receptor homolog from LCDV-C

Tumor necrosis factor receptor (TNFR) plays an important role in the evasion of immune response by large DNA viruses. TNFR is a homologue of cellular receptors. Lymphocystis disease virus, an iriduvirus, isolated in China (LCDV-C) is a large DNA virus. Primers were de signed based on conserved TNFR nucleotide sequences in iridoviruses and used to amplify the homologue in LCDV-C. A DNA fragment of 834 bp was generated and sequenced. The recombinant prokaryotic expression plasmid containing this fragment was constructed and expressed in E. coli. DE3. An expected 45kDa fusion protein was isolated by SDS-PAGE. Computer analysis indicated that LCDV-C TNFR homologue encodes a 278aa putative protein, which contains a typical cysteine-rich domain. It shares 34% identity with flounder TNFRII