Cinquin Lab

A hybrid plasmid for expression of toxic malarial proteins in Escherichia coli

Cinquin O., Christopherson R.I., Menz R.I., Mol. Biochem. Parasitol. 117(2), pp245-247 (2001)


The RIG plasmid [Baca and Hol, 2000, Int. J. Parasitol. 30, 113-118] encodes tRNA genes rare in Escherichia coli, enabling codon-biased Plasmodium genes to be over-expressed in E. coli. Expression of orotidine-5′-monophosphate decarboxylase (EC from Plasmodium falciparum was found to be toxic to E. coli BL21(DE3) cells carrying the RIG plasmid. Unfortunately, the RIG plasmid is incompatible with the pLysS plasmid commonly used with pET expression vectors to allow over-expression of recombinant proteins toxic to E. coli by repressing their basal level expression. We describe here a new hybrid plasmid carrying the gene for T7 lysozyme and those for the rare E. coli codons argU, ileX and glyT, which facilitates over-expression of orotidine-5′-monophosphate decarboxylase (EC from P. falciparum.