Looking for non-coli vector

Michael Benedik bchs1b at Elroy.UH.EDU
Thu Jan 28 00:21:53 EST 1993

In article <9301272018.AA19221 at umailsrv0.UMD.EDU>, William_D_WARREN at UMAIL.UMD.EDU (ww40) writes:
>We are looking for a double stranded, closed circular DNA vector
>that will not replicate in E coli.
>What is needed is a system whereby we can do invitro manipulation and
>easily reintroduce the DNA back into it's host which will then grow it
>up with high fidelity so we can isolate large quantities (around 1-200ug)
>of monomeric molecules. We are currently considering B subtilis plasmids
>however their propensity for concatamerization, instability and poor
>transformation are far from ideal for our purposes. What is important,
>as mentioned above, is that they not replicate in E coli and are double
>stranded closed circles.
>Does anyone out there have any suggestions ???
>Center Ag Biotech
>University of Maryland

It isn't exactly clear what you want to do. But as an alternative, how
about a plasmid which selectively replicates only in certain E. coli
strains or under certain conditions. There are some vectors requiring 
specific replication proteins which need to be provided in trans, usually
from an lambda lysogen. So the plasmid only replicates in these hosts
and not in standard E.coli. I think these are PIR plasmids or something
similar. I can get some references when in my office if you want.
Alternately, there is a vector whose replication is tightly controlled
by lac repressor such that it only replicates in the presence of IPTG.
Would something like this serve your purpose better than using
heterologous strains???

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

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