You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True about collagen is all Except and explain in detail?
COLLAGENS HAVE A TRIPLE HELIX STRUCTUREAll collagen types have a triple helical structure. A striking characteristic of collagen is the occurrence of glycine residues at every third position of the triple helical poion of the alpha chain. This is necessary because glycine is the only amino acid small enough to be accommodated in the limited space available in the central core of the triple helix.This repeating structure, represented as (Gly-X-Y)n, is an absolute requirement for the formation of the triple helix. While X and Y can be any other amino acids, about 100 of the X positions are proline and about 100 of the Y positions are hydroxyproline. Proline and hydroxyproline confer rigidity on the collagen molecule. Hydroxyproline is formed by the post-translational hydroxylation of peptide-bound proline residues catalyzed by the enzyme prolyl hydroxylase, whose cofactors are ascorbic acid (vitamin C) and a-ketoglutarate.Ref: Harper&;s Biochemistry; 30th edition; Chapter 50 The Extracellular Matrix