FIG 2.

Unlike hY132A crystal packing, wY132A crystal packs differently. (a) The asymmetric unit (ASU) of the wY132A crystal structure has two dimers, AB (blue and cyan) and CD (orange and purple). (b) Crystal packing of hY132A (PDB accession number 4BMG) adopts capsid-like interactions to form trimers of dimers (red triangle). (c) Unlike hY132A, the crystallographic ASU of wY132A has two dimers in a base-to-base arrangement. (d) By crystallographic symmetry, the wY132A repeats the ASU to form a cylinder in the crystal. In this packing arrangement, the region around residue 132 for the CD dimer does not contact other proteins.