Unpatented fusion vectors?

[Rick Stowe]

Hello Molecular Biologists,

I am searching for an E. coli expression vector with a gene fusion system 
built in for simplification of purification.  I am aware that there are 
several available from various vendors, but they all seem to carry patent 
protection and licensing agreements for commercial use.

I am also interested in any information concerning the details of 
licensing agreements associated with the commercially available 
expression vectors other than pGEX.

I will appreciate any help I get!  Nobody I've talked to seems to 
know anything about expression vectors without patent restrictions.  
Please feel free to respond to my address at mcmullenix at sprintmail.com if 
you don't wish to post your response.

Thanks!

Michael C. Mullenix, Ph.D.