1WU4

Crystal structure of reducing-end-xylose releasing exo-oligoxylanase

Summary for 1WU4

• Entry DOI: 10.2210/pdb1wu4/pdb
• Related: 1WU5 1WU6
• Descriptor: xylanase Y, NICKEL (II) ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: (alpla/alpha)6 barrel, glycoside hydrolase family 8, hydrolase
• Biological source: Bacillus halodurans
• Total number of polymer chains: 1
• Total formula weight: 46279.59

Authors

Fushinobu, S.,Hidaka, M.,Honda, Y.,Wakagi, T.,Shoun, H.,Kitaoka, M. (deposition date: 2004-12-01, release date: 2005-02-22, Last modification date: 2023-10-25)

Primary citation

Fushinobu, S.,Hidaka, M.,Honda, Y.,Wakagi, T.,Shoun, H.,Kitaoka, M.
Structural Basis for the Specificity of the Reducing End Xylose-releasing Exo-oligoxylanase from Bacillus halodurans C-125
J.Biol.Chem., 280:17180-17186, 2005

PubMed Abstract: Reducing end xylose-releasing exo-oligoxylanase from Bacillus halodurans C-125 (Rex) hydrolyzes xylooligosaccharides whose degree of polymerization is greater than or equal to 3, releasing the xylose unit at the reducing end. It is a unique exo-type glycoside hydrolase that recognizes the xylose unit at the reducing end in a very strict manner, even discriminating the beta-anomeric hydroxyl configuration from the alpha-anomer or 1-deoxyxylose. We have determined the crystal structures of Rex in unliganded and complex forms at 1.35-2.20-A resolution and revealed the structural aspects of its three subsites ranging from -2 to +1. The structure of Rex was compared with those of endo-type enzymes in glycoside hydrolase subfamily 8a (GH-8a). The catalytic machinery of Rex is basically conserved with other GH-8a enzymes. However, subsite +2 is blocked by a barrier formed by a kink in the loop before helix alpha10. His-319 in this loop forms a direct hydrogen bond with the beta-hydroxyl of xylose at subsite +1, contributing to the specific recognition of anomers at the reducing end.

PubMed: 15718242
DOI: 10.1074/jbc.M413693200

Experimental method

X-RAY DIFFRACTION (1.35 Å)