The correct answer is - in the sickle-cell hemoglobin is the replacement of glutamic acid with valine in the β-globin amino acid chain.
Explanation:
Sickle cell anemia has a mutant gene in which that produces has valine amino acid instead of glutamate in the hemoglobin protein. In the given question the structure of the protein has only one difference that is the replacement of the glutamic acid in normal hemoglobin to valine in the β-globin amino acid chain in the mutant protein.
Valine 6 (beta chain) binds to a different hydrophobic patch (on the alpha chain and causes the disease in sickle cell anemia cases.
