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catalytic glycosyltransferase (GT) domain found in the lysyl hydroxylase (LH) family The lysyl hydroxylase (LH) family includes LH1-3. LH1 (EC 1.14.11.4, also called procollagen-lysine,2-oxoglutarate 5-dioxygenase 1 or PLOD1) and LH2 (EC 1.14.11.4, also called procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 or PLOD2) form hydroxylysine residues in -Xaa-Lys-Gly- sequences in collagens. These hydroxylysines may serve as sites of attachment for carbohydrate units and are essential for stability of the intermolecular collagen cross-links. LH1 is part of a complex composed of PLOD1, P3H3 and P3H4 that catalyzes hydroxylation of lysine residues in collagen alpha chains and is required for normal assembly and cross-linking of collagen fibrils. LH3 (EC 1.14.11.4/EC 2.4.1.50/EC 2.4.1.66), also called procollagen-lysine,2-oxoglutarate 5-dioxygenase 3 (PLOD3), or multifunctional procollagen lysine hydroxylase and glycosyltransferase LH3, is a multifunctional enzyme that catalyzes a series of essential post-translational modifications on Lys residues in procollagen. It converts collagen lysines into 1,2-glucosylgalactosyl-5-hydroxylysines through three consecutive reactions: hydroxylation of collagen lysines (LH activity), N-linked conjugation of galactose to hydroxylysines (GT activity), and conjugation of glucose to galactosyl-5-hydroxylysines (GGT activity). LH3 monomer encompasses three domains; the first two N-terminal domains (catalytic glycosyltransferase domain and accessory domain) show Rossmann-fold architectures reminiscent of glycosyltransferases, whereas the C-terminal domain is characterized by a double-stranded beta-helix (DSBH) fold, highly conserved among the 2-oxoglutarate, Fe2+-dependent dioxygenases. This model corresponds to the N-terminal catalytic glycosyltransferase (GT) domain, which is solely responsible for glycosyltransferase activities (both GT and GGT). |
Jiyao W et al.(2023). "The conserved domain database in 2023.",