5glm

Crystal structure of CoXyl43, GH43 beta-xylosidase/alpha-arabinofuranosidase from a compost microbial metagenome in complex with xylotriose, calcium-free form.

spinqualitylabelsall models 5glm, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5glm is a 2 chain structure with sequence from Uncultured bacterium. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: ACT, NA, PRD_900116, PRD_900117, SIN, TRS, XYP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A0H5BL38_9BACT Publication Abstract from PubMed The crystal structure of metagenomic beta-xylosidase/alpha-l-arabinofuranosidase CoXyl43, activated by calcium ions, was determined in its apo and complexed forms with xylotriose or l-arabinose in the presence and absence of calcium. The presence of calcium ions dramatically increases the kcat of CoXyl43 for p-nitrophenyl beta-d-xylopyranoside and reduces the Michaelis constant for p-nitrophenyl alpha-l-arabinofuranoside. CoXyl43 consists of a single catalytic domain comprised of a five-bladed beta-propeller. In the presence of calcium, a single calcium ion was observed at the centre of this catalytic domain, behind the catalytic pocket. In the absence of calcium, the calcium ion was replaced with one sodium ion and one water molecule, and the positions of these cations were shifted by 1.3 A. The histidine-319 side chain, which coordinates to the 2-hydroxyl oxygen atom of the bound xylose molecule in the catalytic pocket, also coordinates to the calcium ion, but not to the sodium ion. The calcium-dependent increase in activity appears to be caused by the structural change in the catalytic pocket induced by the tightly bound calcium ion and coordinating water molecules, and by the protonation state of glutamic acid-268, the catalytic acid of the enzyme. Our findings further elucidate the complex relationship between metal ions and glycosidases. Crystal structure of metagenomic beta-xylosidase/ alpha-l-arabinofuranosidase activated by calcium.,Matsuzawa T, Kaneko S, Kishine N, Fujimoto Z, Yaoi K J Biochem. 2017 Sep 1;162(3):173-181. doi: 10.1093/jb/mvx012. PMID:28204531 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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