Multifunctional enzyme that catalyzes a series of post-translational modifications on Lys residues in procollagen. Plays a redundant role in catalyzing the formation of hydroxylysine residues in -Xaa-Lys-Gly- sequences in collagens (By similarity). Plays a redundant role in catalyzing the transfer of galactose onto hydroxylysine groups, giving rise to galactosyl 5-hydroxylysine (By similarity). Has an essential role by catalyzing the subsequent transfer of glucose moieties, giving rise to 1,2-glucosylgalactosyl-5-hydroxylysine residues. Catalyzes hydroxylation and glycosylation of Lys residues in the MBL1 collagen-like domain, giving rise to hydroxylysine and 1,2-glucosylgalactosyl-5-hydroxylysine residues. Catalyzes hydroxylation and glycosylation of Lys residues in the ADIPOQ collagen-like domain, giving rise to hydroxylysine and 1,2-glucosylgalactosyl-5-hydroxylysine residues. Essential for normal biosynthesis and secretion of type IV collagens. Essential for normal formation of basement membranes (By similarity). 2-oxoglutarate + L-lysyl-[collagen] + O2 = (5R)-5-hydroxy-L-lysyl-[collagen] + CO2 + succinate (5R)-5-hydroxy-L-lysyl-[collagen] + UDP-alpha-D-galactose = (5R)-5-O-(beta-D-galactosyl)-5-hydroxy-L-lysyl-[collagen] + H(+) + UDP (5R)-5-O-(beta-D-galactosyl)-5-hydroxy-L-lysyl-[collagen] + UDP-alpha-D-glucose = (5R)-5-O-[alpha-D-glucosyl-(1->2)-beta-D-galactosyl]-5-hydroxy-L-lysyl-[collagen] + H(+) + UDP Homodimer. The majority of the secreted protein is associated with the extracellular matrix. The N-terminal domain mediates glycosyltransferase activity. The C-terminal domain that mediates lysyl hydroxylase activity is also important for homodimerization.