Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 17

Using the Protein Data Bank to explore the structure and function of glutamate synthase
Go to www.pdb.org and examine the PDB file 1LM1 for glutamate synthase. Find its iron-sulfur cluster and FMN prosthetic group. Discover how this enzyme is organized into an N-terminal domain that functions in ammonia removal from glutamine (the glutaminase domain) and the - ketoglutarate-binding site near the Fe/S and flavin prosthetic groups. Consult van den Heuvel, R. H. H., et al., 2002. Structural studies on the synchronization of catalytic centers in glutamate synthase. Journal of Biological Chemistry 277: 24579-24583, to see how these two sites are connected by a tunnel for passage of ammonia from glutamine to -ketoglutarate.