Type I and type V procollagen triple helix uses different subsets of the molecular ensemble for lysine posttranslational modifications in the rER

Collagen is the most abundant protein in humans. It has a characteristic triple-helix structure and heavily posttranslationally modified. The complex biosynthesis of collagen involves processing by many enzymes chaperones rough endoplasmic reticulum. Lysyl hydroxylase 1 (LH1) required to hydroxylate lysine for cross-linking carbohydrate attachment within triple helical sequences. Additionally, recent study prolyl 3-hydroxylase 3 (P3H3) demonstrated that this enzyme may be critical LH1 activity; however, details surrounding its involvement remain unclear. If P3H3 an chaperone activity, null mice should display similar deficiency lysyl hydroxylation. To test hypothesis, we compared amount location hydroxylysine domains type V I from null, wild-type mice. was reduced mice, but surprisingly contained as much In collagen, our results indicate plays global enzymatic role also involved hydroxylation, particularly at cross-link formation sites, not all hydroxylation sites. summary, suggests likely have two distinct mechanisms recognize different types distinguish sites other collagen.