71057  Rosetta-gami™(DE3)pLysS Competent Cells

This product has been discontinued.

We are offering Rosetta-gami™ 2(DE3)pLacI Competent Cells (Cat. No. 71353) as a possible alternative. Please read the alternative product documentation carefully and contact technical service if you need additional information.

Rosetta-gami™ host strains are Origami derivatives that combine the enhanced disulfide bond formation resulting from trxB/gor mutations with enhanced expression of eukaryotic proteins that contain codons rarely used in E. coli. These strains supply tRNAs for AGG, AGA, AUA, CUA, CCC, and GGA on a chloramphenicol-resistant plasmid. The tRNA genes are driven by their native promoters. In Rosetta-gami(DE3)pLysS, the rare tRNA genes are present on the same plasmid that carries the T7 lysozyme gene. The trxB and gor mutations are selectable on kanamycin and tetracycline, respectively; therefore, these strains cannot be used with the plasmids carrying kanamycin or tetracycline resistance genes.

DE3 indicates that the host is a lysogen of λDE3, and therefore carries a chromosomal copy of the T7 RNA polymerase gene under control of the lacUV5 promoter. Such strains are suitable for production of protein from target genes cloned in pET vectors by induction with IPTG.

pLysS strains express T7 lysozyme, which further suppresses basal expression of T7 RNA polymerase prior to induction, thus stabilizing pET recombinants encoding target proteins that affect cell growth and viability. Genotype: Δ(ara-leu)7697 ΔlacX74 ΔphoA PvuII phoR araD139 ahpC galE galK rpsL (DE3) F′[lac+ lacI^q pro] gor522::Tn10 trxB pLysSRARE (Cam^R, Kan^R, Str^R, Tet^R)