Question

Explain why mutations that replace S/T/N residues with A/L/W residues in the N-terminal region of transmembrane proteins that function as cell surface receptors could significantly disrupt that utility of these proteins as receptors.

Answer 1

Serine (S), Threonine (T) and Asparagine (N) are primary binding sites of carbohydrates, and thereby they are required to form glycoproteins (i.e., glycosylation products)

Step-by-step explanation:

A transmembrane protein (TP) is a particular type of protein that crosses the cell membrane in order to enable the movement of ions and molecules. Transmembrane proteins are divided into alpha-helical and beta-barrel proteins. The N-terminal region of transmembrane glycoproteins can be required for N-linked glycosylation, which is an enzymatic mechanism capable of attaching oligosaccharides to proteins in order to form glycoproteins (glycans). N-linked glycosylation is a posttranslational protein modification that has distinct functions depending on the cell type and the protein region involved in such modification. For example, in the surface of immune cells, the N-linked glycans are capable of dictating the migration pattern of these cells.