What is the four-fold structure of a protein?
Flexi Says:
Some protein molecules consist of multiple protein subunits. The quaternary structure of a protein refers to the specific interaction and orientation of the subunits of that protein Hemoglobin is a very large protein found in red blood cells and whose function is to bind and carry oxygen throughout the bloodstream. Hemoglobin consists of four subunits – two α subunits (yellow) and two β subunits (gray) – which then come together in a specific and defined way through interactions of the side chains (see Figure here). Hemoglobin also contains four iron atoms, located in the middle of each of the four subunits. The iron atoms are part of a structure called a porphyrin, shown in red in the figure.
