Suggestions for expressing two proteins in E. coli

[Steven Goldberg]

I am looking for ideas on how to simulataneously express two recombinant
proteins in E. coli (I know that each one can be expressed separately).
Would it be best to make a poly-cistronic mRNA and have both proteins
transcribed off the same message, or should the promoter be present in
front of both genes?  Or would a two plasmid system be better?  If you
have any experience and/or references on this subject, I would be grateful
to hear from you.

Thanks.

Steve