Human metallothionein-II is synthesized as a stable membrane-localized fusion protein in Escherichia coli.
A synthetic gene encoding human metallothionein-II (HMT) was cloned into the specially constructed high-copy-number expression vector, pUA7, and expressed in Escherichia coli. The plasmid construct includes the promoter/operator and regulatory sequences of the Salmonella typhimurium ara operon and part of the 5'-coding and all of the 3'-noncoding regions of the E. coli lpp. Upon induction with arabinose, the resulting Lpp::HMT fusion protein was produced 75,000-fold over uninduced cells, with a relatively stable mRNA (T1/2 of 8.3 min) and a completely stable protein. In addition, over 95% of the final fusion protein was localized in the outer membrane and was capable of binding heavy metals (especially cadmium) in vitro. Cells producing Lpp::HMT bioaccumulated heavy metals (e.g., cadmium) 66-fold over nonproducing cells.
Jacobs
F A
FA
Biotechnology Research Institute (NRCC), Montreal, Quebec, Canada.
Romeyer
F M
FM
Beauchemin
M
M
Brousseau
R
R
D001089:Arabinose / Q000494:pharmacology; D002104:Cadmium / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D005813:Genes, Synthetic; D005822:Genetic Vectors; D006801:Humans; D008565:Membrane Proteins; D008668:Metallothionein / Q000235:genetics*; D010957:Plasmids; D011993:Recombinant Fusion Proteins
D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D002104:Cadmium; D008668:Metallothionein; D001089:Arabinose