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Protein expression problems in HB101 - (Sep/05/2008 )

I am trying a protein in HB101 that is targeted to the OM and secreted into the culture media. When I induce the protein with 0.5 mM IPTG I see no protein production (I have done varying induction times and ever overnight and have seen nothing). I can express the protein in Rosetta (DE3) pLacI, however I cannot work in this strain because the protein is causing a fair amount of lysis. So my protein is somewhat toxic. I would like to get the protein to express in HB101. My question is why is the protein not expressing in HB101? The only idea I could think of is maybe leaky expression is causing the plasmid to be rearranged or modified. Does this sound reasonable? Any other suggestions? BTW this protein is from a virulent strain of E. coli, so there shouldnt be an issue with codon usage.


What is the vector that you use?