expression of a fusionprotein

Andreas Kampkötter andreas.kampkoetter at
Fri Dec 12 11:59:01 EST 1997

I am trying to express a cDNA coding for a homologue of Ras as a bacterial
fusionprotein (=DF-Galactosidase) in the pUR vectors (Ruether and
Mueller-Hill, 1983). I have cloned the cDNA in all three reading frames and
the clones have been tested by restriction analysis.
After induction of expression (2 mM IPTG) the non-recombinant clone shows a
band of the expected size, but the recombinant clones show bands of the same
size. There is no difference in the size of the band in the non-recombinant
and in the recombinant clones. An antibody directed against Ras (heterolog)
do not detect anything.
Any explanations for this phenomenon or hints to solve this problem are very


Andreas Kampkoetter
Institute for Genetics
Heinrich Heine Universitaet
Universitaetsstr. 1
D-40225 Duesseldorf/Germany

Tel.:   (49)-211-811-2077
e-mail: andreas.kampkoetter at

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