中国生物工程杂志

yggG, a Era-binding protein gene, was isolated and cloned from the E. coli genomic DNA library. Previous studies indicated that the product of yggG gene, YggG294(amino acids 1-294), strongly inhibited the growth of host bacteria and caused the death of bacteria cells. To elucidate the relationship between YggG and Era, we constructed a double promoter expression vector that can express YggG294 and Era proteins controllably in the same time. Using this vector to express YggG294 and Era protein in the same E. coli cells, then analyzed the relation between YggG294 and Era. The results showed that the ratio of Era proteins to total proteins increased with the increase of induction time in E. coli cells without YggG294 expression and with little YggG294 expression, while the ratio of Era proteins to total proteins seemed to be a constant level in E. coli cells overexpressing YggG294. The results of this study also showed that pre-expression of Era protein did not produce any effect on the growth inhibition of E. coli cells caused by YggG294. These results indicate that the expression of YggG294 produced a very strong inhibitory effect on the growth rate of E. coli cells and the overexpression of Era, ant that the interaction between YggG and Era is not associated with the growth inhibition of E. coli cells caused by YggG294.