This domain is found centrally in D-glucuronyl C5-epimerase from humans (Glce) and similar proteins involved in glycan metabolism and heparin biosynthesis in animals. Glce is essential for the reversible epimerisation of D-glucuronic acid (GlcA) into L-iduronic acid (IdoA), contributing to generate functional protein-binding motifs to ensure polymer function. This protein consists of three intertwined domains. This entry represents a classical beta-sandwich domain that consists predominantly of a convex four-stranded beta- -sheet and a concave seven-stranded beta-sheet. It is inserted between two of the helices of the C-terminal alpha-barrel domain (whose most C-terminal region is represented by Pfam:PF06662) [1,2].

1: Structural and functional study of D-glucuronyl C5-epimerase. Qin Y, Ke J, Gu X, Fang J, Wang W, Cong Q, Li J, Tan J, Brunzelle JS, Zhang C, Jiang Y, Melcher K, Li JP, Xu HE, Ding K; J Biol Chem. 2015;290:4620-4630. PMID:25568314

2: Substrate binding mode and catalytic mechanism of human heparan sulfate d-glucuronyl C5 epimerase. Debarnot C, Monneau YR, Roig-Zamboni V, Delauzun V, Le Narvor C, Richard E, Henault J, Goulet A, Fadel F, Vives RR, Priem B, Bonnaffe D, Lortat-Jacob H, Bourne Y; Proc Natl Acad Sci U S A. 2019;116:6760-6765. PMID:30872481