Path: utzoo!attcan!uunet!snorkelwacker!bionet!ORCHID.UCSC.EDU!ludwig
From: ludwig@ORCHID.UCSC.EDU (Bob Ludwig)
Newsgroups: bionet.molbio.methds-reagnts
Subject: E. coli SURE strain, message 2.
Message-ID: <Q6B4747A@legume>
Date: 30 Jul 90 15:43:42 GMT
Sender: daemon@genbank.BIO.NET
Lines: 12

"The E. coli SURE strain carries a copy of the Tn5 element."

I've had a number of requests to elaborate on this message. Tn5 is a
bacterial transposable element conferring resistance to kanamycin and
streptomycin (requires a mutation to do so in E. coli). It transposes to new
DNA loci at a frequency of 10 exp -5 per cell-generation. 

Therefore, recombinant DNA work with kanamycin phosphotransferase genes is
excluded in SURE. Furthermore, any use of SURE as host for recombinant DNA
runs the risk that Tn5 will transpose to these sequences. 

-Bob Ludwig