Repressed pTac leaks ! (Better ?)

Paul N Hengen pnh at
Mon Mar 8 17:56:14 EST 1993

>I have the pTac promoter upstream of a full lacZ in a transcriptional fusion
>vector based on pSC101. The lac repressor is supplied for a single copy
>lacIQ contruct carried as an F plasmid. The host is strain MV1190, a 
>recA derivative of JM101.

[stuff deleted]

>2) Is there a better promoter (met B ?) that can be repressed efficiently
>and still give sufficient promoter activity for in vitro transcription 
>studies ? If so, where can I find it ?
>Thanks very much,

You might want to check into using an expression vector that contains
Ptac AND a copy of lacIq. I've used a set of vehicles called pJF118HE
and pJF118EH. The reference is:

author = "J. Furste
     and W. Pansegrau
     and R. Frank
     and H. Blcker
     and P. Scholz
     and M. Bagdasarian
     and E. Lanka",
title = "Molecular cloning of the plasmid RP4 primase region in a
         multi-host-range tacP expression vector",
journal = "Gene",
volume = "48",
pages = "119-131",
year = "1986"}
Paul N. Hengen
National Cancer Institute
Frederick Cancer Research and Development Center
Frederick, Maryland 21702-1201 USA

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