9j08

From Proteopedia

Acetyl xylan esterase B from Aspergillus oryzae (AoAXEB), succinate complex form

Structural highlights

9j08 is a 1 chain structure with sequence from Aspergillus oryzae RIB40. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.9Å
Ligands:	, ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q2UR69_ASPOR

Publication Abstract from PubMed

Acetyl xylan esterase plays a crucial role in the degradation of xylan, the major plant hemicellulose, by liberating acetic acid from the backbone polysaccharides. Acetyl xylan esterase B from Aspergillus oryzae, designated AoAxeB, was biochemically and structurally investigated. The AoAxeB-encoding gene with a native signal peptide was successfully expressed in Pichia pastoris as an active extracellular protein. The purified recombinant protein had pH and temperature optima of 8.0 and 30 degrees C, respectively, and was stable up to 35 degrees C. The optimal substrate for hydrolysis by purified recombinant AoAxeB among a panel of alpha-naphthyl esters was alpha-naphthyl acetate. Recombinant AoAxeB catalyzed the release of acetic acid from wheat arabinoxylan. The release of acetic acid from wheat arabinoxylan increased synergistically with xylanase addition. No activity was detected for the methyl esters of ferulic, p-coumaric, caffeic, or sinapic acids. The crystal structures of AoAxeB in the apo and succinate complexes were determined at resolutions of 1.75 and 1.90 A, respectively. Although AoAxeB has been classified in the Esterase_phb family in the ESTerases and alpha/beta-Hydrolase Enzymes and Relatives (ESTHER) database, its structural features partly resemble those of ferulic acid esterase in the FaeC family. Phylogenetic analysis also indicated that AoAxeB is located between the clades of the two families. Docking analysis provided a plausible binding mode for xylotriose substrates acetylated at the 2- or 3-hydroxy position. This study expands the current knowledge of the structures of acetyl xylan esterases and ferulic acid esterases that are required for complete plant biomass degradation.

Identification and structural characterization of a novel acetyl xylan esterase from Aspergillus oryzae.,Yamada C, Kato T, Shiono Y, Koseki T, Fushinobu S FEBS J. 2025 Jan 28. doi: 10.1111/febs.17420. PMID:39876052^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Yamada C, Kato T, Shiono Y, Koseki T, Fushinobu S. Identification and structural characterization of a novel acetyl xylan esterase from Aspergillus oryzae. FEBS J. 2025 Jan 28. PMID:39876052 doi:10.1111/febs.17420