Zhixiang Chen: Regarding your question about unexpected expression of
plant mRNAs in your expression library--> Lots of plant genes could have
fortuitous E. coli ribosome binding sites upstream of an ATG: the
consensus ribo binding site is something like AAGGAG- but as little as
AGGA or GAGG will allow some translation. I once was able to massively
express a plant protein in E. coli by simply plopping the full-length
cDNA into bluescript behind the T7 promoter, then transforming an E.
coli strain that expressed T7 RNA pol.ase. The cDNA had an AAGGAG-like
sequence in the 5'UTR just upstream of the initiation AUG.
So, what you suggest is happening in your library is very possible.
Department of Biology
Walla Walla, WA 99362
vernondm at whitman.edu