牛泡沫病毒BFV3026 gag基因的克隆及其在大肠杆菌中的表达

从牛泡沫病毒BFV3026感染的胎牛肺细胞中提取Hirt DNA,PCR扩增BFV3026　gag基因。序列分析确证后，将其克隆于原核表达载体pET32A，重组质粒转化大肠杆菌BL21（DE3），经IPTG诱导，使Gag蛋白得以高效表达。SDS－PAGE及Western blot证实：表达蛋白占菌体总蛋白的40%，本工作的完成为Gag蛋白功能的研究奠定基础。

CLONING OF BFV3026 GAG GENE AND EXPRESSION IN E. coli

With polymerase chain reaction (PCR), a fragment encoding the Gag protein was amplified from the Hirt DNA of bovine foamy virus3026-infected cells, which was isolated previously from the peripheral blood mononuclear cells of an infected cattle in Tianjin.. Sequence analysis revealed that it had high identity with that of the reported BFV in GenBank. Then this gag gene was ligated into plasmid of pET 32A for prokaryotic expression. BL21 (DE3) of E.coli transformed with the recombinant plasmid of pET gag was induced to specifically express the Gag protein in high level. The expressed product was characterized by SDS-PAGE and Western blot analysis, which occupies 40% of total bacterial protein. The report has laid a basis for searching the possible function of Gag in virus assembly.