<prompt> The fold in collagen is because of presence of:HistidineGlycineArginincGlutamate  <response>: The fold in collagen is because of presence of Glycine. ADDITIONAL READING ON STRUCTURE OF COLLAGEN: Collagen is made up of 3 alpha- chains not alpha helix. These 3 chains together make a superhelix -- Tropocollagena rope like triple helix Superhelix right handed is oured by Glycine residues. Glycine has the smallest side chain soit fits into the restricted space where three chains of helix come together. 