At the centre of Vectron's technologies is the highly controllable promoter Pm and its cognate transcription regulator xylS. Pm is an inducible promoter that is tight when uninduced and very strong under maximal induction. It is induced with benzoic acids which are low-cost and non-toxic to both bacteria and humans, and does not exhibit the usual "all-or-nothing" effect as seen with IPTG induced promoters. Through engineering of Pm and xylS, and their 5'-UTR region, novel expression cassettes have been obtained that can rival T7 in expression strength yet still retain their controllable nature. The Pm/xylS expression cassette can be used for controlled expression of proteins in various bacteria, at very high levels, but also for more controlled expression ideal for metabolic engineering. Pm/xylS is usually used in conjunction with minimal replicons of the RK2 plasmid which gives very low metabolic burden, highly stable vectors in the absence of antibiotic selection pressure, and the possibility of increased vector copy number for increased titres, but can also be used on other replicons. In contrast to T7, Pm/xylS does not require specific E. coli strains, and can, to our knowledge, be used for recombinant expression in any E. coli strain.
This technology is covered by the following patent applications: USPTO6258565, EPO922108, USPTO12/376312 , EPO2059599, USPTO12/520139, EPO2078076.