How to aleviate toxicity?

Tracie Matsumoto traciem at
Fri Sep 24 10:29:08 EST 1999

Dear all,

I am trying to clone a membrane protein in both a pBluescript and a
yeast expression vector. However, although I can have it done with the
unmodified sequence, every time I try to modify it (for example, by
adding a tag for immunolocalisation) I get funny plasmids, none at all
or no transformation of E. coli cells. This looks to me as toxicity
(similar proteins also have the same problem).
Does anyone know of a way to reduce this problem when trying to
transform a toxic protein into E. coli? I have heard of adding glucose
to LB or to grow the bacteria at low temperatures but nobody could give
details of these.
Any help would be much appreciated.
Please answer to my directly if possible. I can't check this newsgroups
very often. Thanks!

Agustin Hernandez

e-mail: hernandez at

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