6S24

Crystal structure of the TgGalNAc-T3 in complex with UDP, manganese and the peptide 3

Summary for 6S24

• Entry DOI: 10.2210/pdb6s24/pdb
• Descriptor: Polypeptide N-acetylgalactosaminyltransferase, ALA-THR-GLY-ALA-GLY-ALA-GLY-ALA-GLY-THR-THR-PRO-GLY-PRO, TRIS(HYDROXYETHYL)AMINOMETHANE, ... (9 entities in total)
• Functional Keywords: galnac-ts, galnac-t3, long-range glycosylation preference, (glyco)peptides, molecular dynamics, specificity, enzyme kinetics, fgf23, phosphate homeostasis, transferase
• Biological source: Taeniopygia guttata (Zebra finch); More
• Total number of polymer chains: 2
• Total formula weight: 76035.18

Authors

de las Rivas, M.,Daniel, E.J.P.,Narimatsu, Y.,Companon, I.,Kato, K.,Hermosilla, P.,Thureau, A.,Ceballos-Laita, L.,Coelho, H.,Bernado, P.,Marcelo, F.,Hansen, L.,Lostao, A.,Corzana, F.,Clausen, H.,Gerken, T.A.,Hurtado-Guerrero, R. (deposition date: 2019-06-20, release date: 2019-12-25, Last modification date: 2024-01-24)

Primary citation

de Las Rivas, M.,Paul Daniel, E.J.,Narimatsu, Y.,Companon, I.,Kato, K.,Hermosilla, P.,Thureau, A.,Ceballos-Laita, L.,Coelho, H.,Bernado, P.,Marcelo, F.,Hansen, L.,Maeda, R.,Lostao, A.,Corzana, F.,Clausen, H.,Gerken, T.A.,Hurtado-Guerrero, R.
Molecular basis for fibroblast growth factor 23 O-glycosylation by GalNAc-T3.
Nat.Chem.Biol., 16:351-360, 2020

PubMed Abstract: Polypeptide GalNAc-transferase T3 (GalNAc-T3) regulates fibroblast growth factor 23 (FGF23) by O-glycosylating Thr178 in a furin proprotein processing motif RHTR↓S. FGF23 regulates phosphate homeostasis and deficiency in GALNT3 or FGF23 results in hyperphosphatemia and familial tumoral calcinosis. We explored the molecular mechanism for GalNAc-T3 glycosylation of FGF23 using engineered cell models and biophysical studies including kinetics, molecular dynamics and X-ray crystallography of GalNAc-T3 complexed to glycopeptide substrates. GalNAc-T3 uses a lectin domain mediated mechanism to glycosylate Thr178 requiring previous glycosylation at Thr171. Notably, Thr178 is a poor substrate site with limiting glycosylation due to substrate clashes leading to destabilization of the catalytic domain flexible loop. We suggest GalNAc-T3 specificity for FGF23 and its ability to control circulating levels of intact FGF23 is achieved by FGF23 being a poor substrate. GalNAc-T3's structure further reveals the molecular bases for reported disease-causing mutations. Our findings provide an insight into how GalNAc-T isoenzymes achieve isoenzyme-specific nonredundant functions.

PubMed: 31932717
DOI: 10.1038/s41589-019-0444-x

Experimental method

X-RAY DIFFRACTION (2.12 Å)