6k0h

Crystal Structure of UDP-glucose 4-epimerase from Bifidobacterium longum in complex with NAD+ and UDP-GlcNAc

spinqualitylabelsall models 6k0h, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6k0h is a 1 chain structure with sequence from Bifidobacterium longum subsp. longum JCM 1217. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: MG, NAD, PEG, UD1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GALE_BIFL2 Involved in the metabolism of galactose. Catalyzes the conversion of UDP-galactose (UDP-Gal) to UDP-glucose (UDP-Glc) through a mechanism involving the transient reduction of NAD. Can also epimerize UDP-GalNAc to UDP-GlcNAc. Involved in the lacto-N-biose I/galacto-N-biose (LNB/GNB) degradation pathway, which is important for host intestinal colonization by bifidobacteria. Publication Abstract from PubMed Infant gut-associated bifidobacteria has a metabolic pathway that specifically utilizes lacto-N-biose I (Gal-beta1,3-GlcNAc) and galacto-N-biose (Gal-beta1,3-GalNAc) from human milk and mucin glycans. UDP-glucose 4-epimerase (GalE) from Bifidobacterium longum (bGalE) catalyzes epimerization reactions of UDP-Gal into UDP-Glc and UDP-GalNAc into UDP-GlcNAc with the same level of activity that is required to send galacto-hexoses into glycolysis. Here, we determined the crystal structures of bGalE in three ternary complex forms: NAD(+)/UDP, NAD(+)/UDP-GlcNAc, and NAD(+)/UDP-Glc. The broad specificity of bGalE was explained by structural features of the binding pocket for the N-acetyl or C2 hydroxy group of the substrate. Asn200 is located in a pocket of the C2 group, and its side chain adopts different conformations in the complex structures with UDP-Glc and UDP-GlcNAc. On the other side, Cys299 forms a large pocket for the C5 sugar ring atom. The flexible C2 pocket and the large C5 pocket of bGalE are suitable for accommodating both the hydroxy and N-acetyl groups of the substrate during sugar ring rotation in the catalytic cycle. The substrate specificity and active site structure of bGalE were distinct from those of Esherichia coli GalE but similar to those of human GalE. Structural basis for broad substrate specificity of UDP-glucose 4-epimerase in the human milk oligosaccharide catabolic pathway of Bifidobacterium longum.,Nam YW, Nishimoto M, Arakawa T, Kitaoka M, Fushinobu S Sci Rep. 2019 Jul 31;9(1):11081. doi: 10.1038/s41598-019-47591-w. PMID:31366978 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also UDP-galactose 4-epimerase

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