What effect does the mutation causing sickle cell anemia have on the amino acid sequence?

The mutation causing sickle cell anemia specifically involves a point mutation in the gene that encodes the beta chain of hemoglobin. This single nucleotide substitution results in the replacement of the amino acid glutamic acid, which is normally present, with valine.

Glutamic acid is a hydrophilic amino acid, whereas valine is hydrophobic. This change alters the properties of the hemoglobin molecule, leading to the formation of abnormal hemoglobin known as hemoglobin S (HbS). Under low oxygen conditions, this altered hemoglobin causes red blood cells to form a characteristic sickle shape, which can lead to blockages in blood vessels and various health complications associated with sickle cell anemia.

The nature of the mutation is crucial in understanding the disease, as it changes the overall structure and function of the hemoglobin protein, which is responsible for carrying oxygen in the bloodstream. This highlights the significant impact that even a single amino acid change can have on a protein's functionality and, subsequently, on human health.