Figure 1.

Overall structures of Hd _1NES1NiR in trimeric and hexameric forms. (a) Top (upper) and side (lower) views of a trimeric Hd _1NES1NiR, colored green, magenta and cyan for each monomer. Threefold axis symmetry is indicated by a black closed triangle (upper) and black line (lower). The T1Cu and T2Cu ions in the core domain and T1Cu_N ion in the extra cupredoxin domain are shown by deep-blue spheres. (b) Side view of a hexameric Hd _1NES1NiR coloured green, magenta and cyan for each monomer generated by crystallographic symmetry. Threefold axis symmetry for each trimer is indicated by a black line. The interaction interface between the two trimers through extra cupredoxin domains is indicated by a black broken line. The T1Cu and T2Cu ions in the core domain and T1Cu_N ion in the extra cupredoxin domain are represented by deep-blue spheres.