The integrative constitutive LEXSY is the basic architecture which permits efficient production of a large variety of proteins. It is based on integration of an expression cassette into the chromosomal ssu-locus encoding the tandem 18S rRNA genes. This cluster is transcribed by the endogenous RNA Polymease I. Due to the expression profile of RNA Polymease I expression of target proteins parallels growth of the culture.
Dependent upon the cloning strategy target proteins are either steadily expressed in the cytoplasm of the host or secreted into the growth medium. Cytosolically expressed proteins can be isolated from easily disrupted cells, whereas secreted proteins are efficiently isolated from the medium by one-step affinity chromatography.
We recommend the standard kit with the vector pLEXSY-sat2 for selection of LEXSY expression strains with the antibiotic Nourseothricin (NTC).
Besides the sat marker, vectors with three other selection markers (ble, hyg, neo) are available. Expression vectors with all four alternative markers can be introduced into the same cell for coexpression of up to four proteins.
All components of the kits are available also separately.
Download the LEXSY vector maps and sequences at: