A MODIFIED PET VECTOR THAT AUGMENTS HETEROLOGOUS PROTEIN EXPRESSION

We describe a modification which can be carried out on the pET vector series that destroys the rop function in these vectors. The modified v ectors have the following advantages : i) increased plasmid copy numbe r, ii) augmented heterologous protein expression of the target gene, i ii) elimination of plasmid incompatibility, and iv) they are smaller i n size, consequently, they have higher transformation efficiency and c an accommodate larger DNA inserts. Additionally, several restriction s ites become unique allowing easier restriction mapping of inserts when required.