| Definition: |
A glycoprotein biosynthetic process starting with the covalent linkage of galactose via a beta-glycosidic bond to the oxygen atom of the hydroxyl group of a hydroxyproline or a hydroxylysine in a protein, which can be further elongated with the sequential addition of sugar units resulting in the formation of a protein O-linked glycan. Hydroxylysine modification occurs in the endoplasmic reticulum and is predominantly found in collagen. Hydroxyproline modification occurs in the Golgi and is found only in plant proteins. |