9SD4

Human PGGHG crystal structure

9SD4 の概要

• エントリーDOI: 10.2210/pdb9sd4/pdb
• 分子名称: Protein-glucosylgalactosylhydroxylysine glucosidase, CHLORIDE ION (3 entities in total)
• 機能のキーワード: collagen, glycosylhydrolase, pgghg, sugar binding protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 80819.12

構造登録者

Casas-Florez, D.,Ortega-Garcia, R.,Sanz-Aparicio, J.,Gonzalez, B. (登録日: 2025-08-12, 公開日: 2026-02-11)

主引用文献

Casas-Florez, D.,Ortega-Garcia, R.,Sanz-Benito, P.,Monterroso, B.,Sanz-Aparicio, J.,Gonzalez, B.
The structure of human glucosidase PGGHG reveals a very specific active site accessible through a flat surface for collagen approximation.
Int.J.Biol.Macromol., 345:150556-150556, 2026

PubMed Abstract: The enzyme glucosylgalactosylhydroxylysine glucosidase (PGGHG) plays a critical role in collagen metabolism by hydrolyzing the 2-O-α-d-glucopyranosyl-O-β-d-galactopyranose, a natural disaccharide found in the glycosylation of hydroxylysine residues in collagen. We report the X-ray crystallographic structure of human PGGHG, revealing the canonical four-domain fold of enzymes from the GH65 family and representing the first structure reported for a mammalian enzyme in this family. A distinctive flat surface adjacent to the catalytic site, shaped by the N-terminal β-sheet and specific conformations of catalytic loops, is unique to PGGHG among GH65 enzymes. Structural complexes with glucose and the substrate analogue kojibiose (KJB), along with site-directed mutagenesis and enzyme assays, identify residues critical for catalysis and hydroxylysine-collagen binding. Docking studies and AlphaFold3-based predictions suggest that the flat surface facilitates the contact between PGGHG and collagen peptides as well as substrate recognition, and support the enzyme's high specificity toward its glucosaccharide substrate. These findings provide structural insight into the selective recognition of glycosylated hydroxylysines and may inform future therapeutic or biotechnological applications targeting collagen metabolism.

PubMed: 41605404
DOI: 10.1016/j.ijbiomac.2026.150556

実験手法

X-RAY DIFFRACTION (2.39 Å)