Construction of gene expression system using virulent phages.

一些枯草芽孢杆菌纳豆噬菌体基因组中携带γ -聚谷氨酸水解酶基因，该基因在噬菌体裂解周期中强烈表达。为了将该系统应用于外源基因表达系统，我们测定了噬菌体phiNIT1的全基因组序列，并分析了γ - pga水解酶基因的表达系统。结果发现，该基因的表达不仅需要噬菌体编码元件，还需要细菌中的顺式元件和反式元件。此外，我们还鉴定了参与宿主细胞表面特异性识别的噬菌体蛋白。

Some Bacillus subtilis natto phages carry gamma-poly glutamate hydrolase gene on their genome, and this gene is strongly expressed during phage lytic cycle. To apply this system for the foreign gene expression system, we determined complete genome sequence of phage phiNIT1 and analyzed the expression system of gamma-PGA hydrolase gene.As a result, we found that not only phage encoded elements but also both of cis-elements and trans-elements in the bacterium were required for the gene expression. In addition, we identified phage proteins involving in specific recognition of host cell surface.