transports oxygen
Hemoglobin is a protein that transports oxygen throughout the body. Source: Image from the RCSB PDB www. org of PDB ID 1I3D R. Kidd, H. Baker, A. Mathews, T. Brittain, E. Baker 2001 Oligomerization and ligand binding in a homotetrameric hemoglobin: two high-resolution crystal structures of hemoglobin Bart's gamma 4 , a marker for alpha-thalassemia. Protein Sci. 1739 1749 . Figure 18.8 Levels of Structure in Proteins Saylor URL: http://www. saylor. org/books.