Most common secondary structure of protein Myosin in muscle and -keratin in hair are,

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Myosin in muscle and -keratin in hair are examples of fibrous proteins. The most common secondary structure in both of these proteins is the -helix. In -keratin, the polypeptide chains are coiled into a right-handed -helix. Similarly, the tail region of myosin consists of two -helices coiled around each other to form a coiled-coil structure. Thus, both proteins predominantly exhibit an -helical secondary structure. Answer: both -helical