The overall structure of AaNusG with three loosely tethered domains [Knowlton, Bubunenko, Andrykovitch, Guo, Routzahn, Waugh, Court, and Ji. Biochemistry (Accelerated Publications) 2003; 42:2275-2281. Abstract]. Helices are shown as blue spirals, b-strands as yellow arrows, loops as gray tubes with the flexible linker in red. A surface representation of AaNusG is also shown.