I have tried putting the arg gene and another chlamy gene together
on one plasmid. The plasmid was extremely large, and turned out to be
to unstable in E. coli for the approach to be feasible. I even tried
using a variety of vectors, including a yeast shuttle vector that would
have been lower copy number in E. coli, but that didn't really help.
This pretty much tells you what you already knew in your heart.
I would just advise those interested that without a minigene you may
be looking at trouble.
ellis at wustlb.wustl.edu