Catalyzes the post-translational formation of 4-hydroxyproline in -Xaa-Pro-Gly- sequences in collagens and other proteins.
Subcellular locations: Endoplasmic reticulum lumen
Highly expressed in placenta, liver and fetal skin. Weakly expressed in fetal epiphyseal cartilage, fetal liver, fibroblast, lung and skeletal muscle. Expressed also in fibrous cap of carotid atherosclerotic lesions.