Fig. S6.

The TtuA-TtuB-Fe-S-AMPPNP-tRNA pentamer complex model. The pentamer complex model was prepared by superposing the TtuA-TtuB complex and the TilS-tRNA complex structure (PDB ID code 3A2K) onto the TtuA-Fe-S-AMPPNP complex. For clarity, a part of the tRNA located in the tunnel is shown. Note that the location of the substrate base of TtuA (position 54) is different from that of TilS (position 34). (A) Sectional view of the pentamer complex model (cyan, TtuA; red, TtuB; yellow, tRNA fragment). The [4Fe-4S] cluster and AMPPNP are shown in the same manner as described above. (B) Close-up view of the catalytic center of the model structure. The expected location of the C terminus of TtuB is shown as a red dotted line.