BIOMOLECULE: 1 THIS ENTRY CONTAINS THE CRYSTALLOGRAPHIC ASYMMETRIC UNIT WHICH CONSISTS OF 4 CHAIN(S) ...BIOMOLECULE: 1 THIS ENTRY CONTAINS THE CRYSTALLOGRAPHIC ASYMMETRIC UNIT WHICH CONSISTS OF 4 CHAIN(S). Applying the 2-fold crystallographic operator (along the c axis) to the tetramer AU will create a molecular octamer of TB-RBP discussed in the corresponding paper. The actual biological state of the molecule is still under question.
The asymmetric unit contains four TB-RBP monomers, each interacting to form a tetramer. A second tetramer produced by two-fold rotation of the crystallographic c axis forms an octamer of TB-RBP in the crystal.