Part of a complex composed of PLOD1, P3H3 and P3H4 that catalyzes hydroxylation of lysine residues in collagen alpha chains and is required for normal assembly and cross-linkling of collagen fibrils (By similarity). Forms hydroxylysine residues in -Xaa-Lys-Gly- sequences in collagens (PubMed:8621606, PubMed:10686424, PubMed:15854030). These hydroxylysines serve as sites of attachment for carbohydrate units and are essential for the stability of the intermolecular collagen cross-links (Probable). 2-oxoglutarate + L-lysyl-[collagen] + O2 = (5R)-5-hydroxy-L-lysyl-[collagen] + CO2 + succinate Homodimer (By similarity). Identified in a complex with P3H3 and P3H4 (By similarity). The disease is caused by variants affecting the gene represented in this entry.