ung E.coli strains

[the End]

In planning a chemical mutagenesis that will involve cytosine deamination,
I need an E. coli strain that will tolerate the presence of uridylate residues
in plasmid DNA, but will propagate them as A-T basepairs, rather than A-U pairs
We currenttly use CJ236 as a host which will introduce deoxyuridine. Are there
many ung only strains out there ? 

Any leads appreciated,


Jim
J. Graham
Biology and Chemistry Depts.
Indiana University -Bloomington