4C1P: Geobacillus thermoglucosidasius GH family 52 xylosidase

Citation:
Abstract
Geobacillus thermoglucosidasius is a thermophilic bacterium that is able to ferment both C6 and C5 sugars to produce ethanol. During growth on hemicellulose biomass, an intracellular beta-xylosidase catalyses the hydrolysis of xylo-oligosaccharides to the monosaccharide xylose, which can then enter the pathways of central metabolism. The gene encoding a G. thermoglucosidasius beta-xylosidase belonging to CAZy glycoside hydrolase family GH52 has been cloned and expressed in Escherichia coli. The recombinant enzyme has been characterized and a high-resolution (1.7 A) crystal structure has been determined, resulting in the first reported structure of a GH52 family member. A lower resolution (2.6 A) structure of the enzyme-substrate complex shows the positioning of the xylobiose substrate to be consistent with the proposed retaining mechanism of the family; additionally, the deep cleft of the active-site pocket, plus the proximity of the neighbouring subunit, afford an explanation for the lack of catalytic activity towards the polymer xylan. Whilst the fold of the G. thermoglucosidasius beta-xylosidase is completely different from xylosidases in other CAZy families, the enzyme surprisingly shares structural similarities with other glycoside hydrolases, despite having no more than 13% sequence identity.
PDB ID: 4C1PDownload
MMDB ID: 119321
PDB Deposition Date: 2013/8/13
Updated in MMDB: 2018/06
Experimental Method:
x-ray diffraction
Resolution: 2.634  Å
Source Organism:
Similar Structures:
Biological Unit for 4C1P: dimeric; determined by author and by software (PISA)
Molecular Components in 4C1P
Label Count Molecule
Proteins (2 molecules)
2
Beta-xylosidase
Molecule annotation
Chemicals (6 molecules)
1
2
2
2
3
2
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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