Clones genes that don't express

Doon bbbbre01 at uctvax.uct.ac.za
Fri Apr 16 08:17:53 EST 1993


Will Bourne and I are working on a theory as to why certain cloned genes
that should express in Ecoli don't.  If you have a clone
that you expected to express, but did not, we would appreciate 
it if you would  tell us the sequence of that clone.


------Included message from Will ------------------------------------>
We are conducting some research on codon usage in E.Coli and
need to find examples of cloned genes that display certain
characteristics that would not normally be reported in the
literature. The genes need to have the following features:

1) They must be from organisms other than E.Coli

2) The complete sequence must be known and if possible
available on one of the data bases

3) The sequence must have been cloned in E.Coli as an in
frame translational fusion, behind an active E.Coli promoter
and known E.Coli ribosome binding site

4) When the ORF is cloned as described above it must give
bizarre or inexplicable results in that expression of the
gene is weak or does not occur at all, when it is reasonable
to expect expression to occur.

5) This lack of expression should be alleviated by a change
in the growth conditions and work in unexpected ways.

For example, if you were working with a DNA damage repair
gene from Bacillus and it was cloned as a translation fusion
but would only express on minimal medium but not on complex
medium (or vice versa) then that is exactly the type of gene
we are looking for. We are especially interested in systems
where the expression is known to be linked to a particular
single compound, eg. glucose or an individual amino acid.

We would be very grateful, if you have or know of such
genes, if you would send us details such as references, data
base accession numbers and unpublished experimental
observations that you feel you can pass on.
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