The complete breakdown of GM2 gangliosides in neurons requires 3 polypeptides. The HEXA enzyme consists of two subunits (called the and subunits), while

The complete breakdown of GM2 gangliosides in neurons requires 3 polypeptides. The HEXA enzyme consists of two subunits (called the α and β subunits), while the third polypeptide (called GMs activator protein) is a small transport protein that moves the gangliosides in the cell. A mutation any one of these genes can result in ganglioside buildup, mutations in the α subunit result in Tay Sachs disease.

How many genes are associated with the proper breakdown of GM2 gangliosides? Explain your reasoning. Discuss how a single amino acid change can result in a non-functional protein and explain how amino acids of different chemical properties might impact a protein. Where in this protein would an amino acid change potentially cause the biggest problem? What type(s) of domain(s) might you expect to see in the HEXAα subunit?