[Xplor-nih] how to build a symmetric oligomer

[Lei Shi]

Hi all,
          I want to build an symmetric pentamer structure using one  
monomer structure and inter-monomer NOEs.  The secondary structure of  
the monomer will be kept fixed. First, how can I keep the symmetry  
during the refinement. Second, I am trying to use the 'group'  
function in xplor. Are all the translation and rotation motions of  
the grouped list allowed? Is there some way to control these motion  
and allow motions along certain direction, such as translate along x  
and rotate about z axis?
          Thanks,
           Lei