tightest promoter expression

[Michael Benedik]

In article <920912.145229.eboye at pcdnr35>, eboye at radium.uio.no (Erik Boye) writes:
>
>It seems to me that you have three options:
>1. The more easily tac-like promoters used in Herman Bujard's expression
>vectors. I believe the promoter contains more operators.
>2. The arabinose promoter, which has been used to clone genes for 
>relatively toxic gene products.
>3. The lambda pL promoter, which may be the best repressed promoter of 
>the three (with excess cI857 repressor present). However, you will need
>a temperature upshift to induce transcription.

You can also use T7 in vitro where the T7 polymerase is regulated
either by lambda pL (temperature induction) or Plac (IPTG induction)
the induction serves to turn on expression of T7 polymerase and hence
results in a tightly regulated system which is quite inducible.
See recent manuscripts by Studier et al

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 Michael Benedik				INTERNET: Benedik at uh.edu
 Dept. of Biochemical & Biophysical Sciences	
 University of Houston				BITNET: Benedik at uhou
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