genotype of e coli strain for protein expression - (Jun/10/2014 )
Hi,
Note sure if this is the right sub-forum for this question - in case it is, kindly let me know and I'll move it. I need some help with understanding genotype of a strain that we're using for protein expression
I'm currently using a Keio collection strain from CGSC (Strain BW25113, CGSC# 7636).
Genotype is as follows:
- Sex(Hfr,F+,F-,or F'): F-
- 6 Mutations:
- DE(araD-araB)567 Δ(araD-araB)567
- lacZ4787(del)(::rrnB-3) ΔlacZ4787(::rrnB-3)
- LAM- λ-
- rph-1 rph-1
- DE(rhaD-rhaB)568 Δ(rhaD-rhaB)568
- hsdR514 hsdR514
I was wondering if this strain could be used for arabinose induced expression. The authors/creators of the Keio collection seemed to have used L-arabinose to induce expression of a vector transformed into this strain.
A more fundamental question would be : will the lack of genes starting 25bp upstream of araB start codon all the way up to 8bp following araD start codon, while leaving the araBAD promoter intact and the araC gene intact allow this strain to be used with a pBAD vector for a tightly regulated expression system?
From the information and links provided on this page, it would seem that the DE(araD-araB) mutation is for regulation of the arabinose promoter - so it should work with arabinose induction.
No idea about the pBAD vector though.
Just in case anyone is interested / future reference - to use the pBAD vector for protein expression, you need to have araB, C, and D to be deleted. Although I have no clue why the araC needs to be knocked out - all you'll have is an extra copy of araC.