Conformational changes in citrate synthase

Here we can see open and closed conformation on the corresponding picture. The C atoms of the small domain in each subunit of the enzyme are green, and those of the large domain are purple. N, O, and S atoms in both domains are blue, red, and yellow. Upon binding oxaloacetate, the smaller domain undergoes an 18 degree rotation relative to the larger domain, which closes the cleft. This generates the acetyl CoA binding site.