Crystallographic Symmetry

Dear Modellers,

Is it possible to incorporate crystallographic symmetry in Modeller in order to generate models of monomer proteins that form large multimers?

I guess it is probably easier to generate the other protein segments of a structure to be modelled, and model a homologous sequence for all segments, although this would be computationally expensive.

If it is possible - how would it be done?

Yours,

Derek Smith