FIG. 7.

Cartoon diagram of TmNtrPrxC40S structure. (A) TmNtrPrxC40S dimer is shown in the middle with FMN, SO₄ molecules into the active sites and into the cavities formed by the absence of the first amino acid, and MPD solvent molecule shown as stick models. In blue subunit A, magenta subunit B, yellow disulfide bonds. Around, zoom of the four active sites of the protein. Red spheres represent the water molecules located in these sites. (B) Crystal packing and intermolecular interactions. Prx modules are colored in marine and pink, and Ntr modules are colored in blue and magenta, in the A and B chains, respectively. On the left, view along the a-axis of two TmNtrPrxC40S dimer symmetrically related, linked via the Prx module. These bricks are piled along the a-axis forming channels. On the right, the two different networks of contact between Prx modules that promote the formation of these channels. At top: Ser38 A/Asn51 B_sym (3.0 Å), Arg42 A/Asn51 B_sym (3.1 Å), Glu124 A/Lys131 B_sym (2.6 Å). At bottom: Ser38 B/His6 A_sym (3.4 Å), SO₄ B/Lys5 A_sym (2.7 Å). (To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars.)