Need help to find a protein expression protocol for cysteine cross linked dimers

[Nirosha Gunasekara]

Hello All,

I need help to choose a vector to express a cysteine cross linked  
dimeric fragment and the monomeric fragment of a protien for NMR  
structure determination.   Since I need to express just a part of a  
protein what are the limitations (or things to consider) when choosing  
an expression vector as well as purification of dimeric and monomeric  
proteins? Which vector(s) may be good candidates?  Does choosing a  
vector depend on the cysteine cross linking procedure? I am wondering  
whether vector, pEZZ18 (Amersham Bio) can be used to express just a  
part of a protien as I read that the expression by pEZZ18 is  
controlled by the lacUV5 and protein A promoters and is not inducible.  
  I am new to molecular cloning and could you please clarify this as  
well.  If you could suggest a common protocol for the expression of  
cysteine cross linked dimers or provide me with a direction to look  
for that would be ideal.  All your help is greatly appreciated.

Thank you very much!
Nirosha