Our lab is trying to overexpress and isolate a rather large yeast (S.
cerevisiae) protein in E.coli. The gene is ca. 4 kb and encodes a protein
of 1,433 a.a. We transformed DH5alpha with a plasmid containing the
gene, but are unable to see it. Also, when the expression is induced
(IPTG), the E.coli become sick (grow slower). Does anyone have any
experience expressing large or toxic proteins in E.coli? Any help
would be greatly appreciated.
-Al (plummer at em.uni-frankfurt.de)