Data items in the PDBX_STRUCT_MSYM_GEN category record details about
the generation of the minimal asymmetric unit. For instance, this
category can be used to provide this information for helical and point
symmetry systems. The PDBX_STRUCT_MSYM_GEN data items provide the
specifications of the components that constitute the asymmetric unit
in terms of cartesian transformations of deposited coordinates.
loop_
_pdbx_struct_msym_gen.msym_id
_pdbx_struct_msym_gen.entity_inst_id
_pdbx_struct_msym_gen.oper_expression
A A 3
B B 4
C B 5