Fig. 5.

On the left, subunit orientation in the asymmetric unit of the crystal lattice of BmTrxR in the C2221 space group. The TrxR domain of subunit c is in deep teal while the TrxR domains of the a/b physiological dimer are in grey and light blue. The Grx domain of subunit c is in deep green while the Grxs of the a/b dimer are both in green. C22 in the Grx domain of subunit a (C22a), belonging to the a/b physiological dimer, faces C22 of subunit c (C22c) of an adjacent unit cell; the C-terminus of subunit “b” is caught between these two cysteines. In the magnifications on the right, in A, the Fo-Fc difference electron density map (in green meshes) contoured at 3σ indicates the presence of a ligand simultaneously linked to C22a and C22c and, in B, the 2Fo-Fc contoured at 1σ (in blue meshes) with the last residues of the C-terminus fitted (GCUC) is shown. E586b is 30 Å apart from the G595b (heteroatoms are in CPK colors). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)