True regarding collagen synthesis is all except
Synthesized in ribisomes as preprocollagen
Hydroxylation of proline occurs in Golgi apparatus
Hydroxylation of lysine occurs in ER
Triple helix assembly occurs in ER
The collagen is synthesized by fibroblasts intracellularly, as a large precursor called procollagen.the extracellular procollagen is cleaved by specific peptidases to form tropocollagen. The hydroxylation of proline and lysine residues of collagen is apost- translational modification taking place intracellularly.Prolyl hydrxylase and lusyl hydroxylase are both di-oxygenases using molecular oxygen. The hydroxylated polypeptides are next glycosylated.The glycosylation occurs only on the hydroxylysine residues. Extracellular maturion of collagen occurs. The collagen is arod like structure.Each of the 3 polypeptide chains is held in a helical conformation by winding around each other. REFERENCE : DM VASUDEVAN TEXTBOOK. SEVENTH EDITION ; PAGE NO:721.
Structure and function of protein