now i have transformed pqe 30 clone into the m15 host successfully, can someone let me know exactly what was reason behind the problem into transformation??is it leaky expression into the other host that is toxic for the cells,if it so then will i would be able to get good expression into this host???
atul -----Original Message----- From: CCP4 bulletin board on behalf of ar...@xtals.org Sent: Tue 5/5/2009 6:24 AM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] problem in transformation of pqe 30 clone To clarify: I am not implying that I've worked with many proteins that express better in XL1-blue cells than they would express in BL21(DE3) or such if cloned into a pET vector or similar. In fact I can probably recall only one or two that expressed *better* in XL1 cells. However in the good old days pQE series of vectors was quite commonly used and I had things in that were inherited from others - these 'things' were fairly simple to express in XL1-blue whereas they gave me loads of trouble in other strains and I was too busy/lazy to re-clone them. Artem > Hello Artem, > > We express almost all our proteins in BL21 derivatives. It sounds > like you've worked with many proteins that express/behave better in > XL1-Blue? > > > ho > UC Berkeley > > ------------------------------------------------------------------------------------------------- > XL1-Blue is a strain of E. coli. Whether it is or isn't an expression host > depends on the definition, and I am not going to argue semantics. > > The T5 promoter works with regular garden variety RNApol of E. coli. > Therefore ANY E. coli strain is an 'expression host' for vectors that > contain this promoter. > > I've expressed many proteins in XL1-Blue and I see no reason why you can't > express yours, either. > > Artem >
