| GO | Name |
| GO:0004656 | procollagen-proline 4-dioxygenase activity |
| GO:0005506 | iron ion binding |
| GO:0005783 | endoplasmic reticulum |
| GO:0005788 | endoplasmic reticulum lumen |
| GO:0016702 | oxidoreductase activity, acting on single donors with incorporation of molecular oxygen, incorporation of two atoms of oxygen |
| GO:0018401 | peptidyl-proline hydroxylation to 4-hydroxy-L-proline |
| GO:0030199 | collagen fibril organization |
| GO:0031418 | L-ascorbic acid binding |