synthetic E coli promoter?

Chris Boyd chrisb at
Wed Jun 2 08:16:51 EST 1999

John Dixon (jpcd100 at wrote:

: I wish to place an oligo upstream of the neomycin phosphotransferase
: cassette in a construct of mine to so that it also confers kanamycin
: resistance in E coli. I have a convenient site in between the
: eukaryotic promoter and the neo ATG. 

Have you checked your plasmid doesn't already confer kanamycin
resistance in E. coli?  Try a range of kanamycin concentrations, say
5--25 ug/ml, with plasmid-free bugs as -ve controls. There may well be
a cryptic bacterial promoter upstream. There ALWAYS is when you DON'T
want one.

: What is the mininmum consensus sequence for a promoter active in E coli?

See Duncan's reply.

Best wishes,
Chris Boyd                      | from (but not \  MRC Human Genetics Unit
Christopher.Boyd at  | on behalf of) /      Crewe Rd, Edinburgh          EH4 2XU, SCOTLAND

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