6AGQ

Acetyl xylan esterase from Paenibacillus sp. R4

Summary for 6AGQ

• Entry DOI: 10.2210/pdb6agq/pdb
• Descriptor: acetyl xylan esterase, ZINC ION (3 entities in total)
• Functional Keywords: paenibacillus sp., acetyl esterase, acetyl xylan esterases, hydrolase
• Biological source: Paenibacillus sp. R4
• Total number of polymer chains: 6
• Total formula weight: 217459.96

Authors

Park, S.,Lee, C.W.,Lee, J.H. (deposition date: 2018-08-13, release date: 2018-10-10, Last modification date: 2024-03-27)

Primary citation

Park, S.H.,Yoo, W.,Lee, C.W.,Jeong, C.S.,Shin, S.C.,Kim, H.W.,Park, H.,Kim, K.K.,Kim, T.D.,Lee, J.H.
Crystal structure and functional characterization of a cold-active acetyl xylan esterase (PbAcE) from psychrophilic soil microbe Paenibacillus sp.
PLoS ONE, 13:e0206260-e0206260, 2018

PubMed Abstract: Cold-active acetyl xylan esterases allow for reduced bioreactor heating costs in bioenergy production. Here, we isolated and characterized a cold-active acetyl xylan esterase (PbAcE) from the psychrophilic soil microbe Paenibacillus sp. R4. The enzyme hydrolyzes glucose penta-acetate and xylan acetate, reversibly producing acetyl xylan from xylan, and it shows higher activity at 4°C than at 25°C. We solved the crystal structure of PbAcE at 2.1-Å resolution to investigate its active site and the reason for its low-temperature activity. Structural analysis showed that PbAcE forms a hexamer with a central substrate binding tunnel, and the inter-subunit interactions are relatively weak compared with those of its mesophilic and thermophilic homologs. PbAcE also has a shorter loop and different residue composition in the β4-α3 and β5-α4 regions near the substrate binding site. Flexible subunit movements and different active site loop conformations may enable the strong low-temperature activity and broad substrate specificity of PbAcE. In addition, PbAcE was found to have strong activity against antibiotic compound substrates, such as cefotaxime and 7-amino cephalosporanic acid (7-ACA). In conclusion, the PbAcE structure and our biochemical results provide the first example of a cold-active acetyl xylan esterase and a starting template for structure-based protein engineering.

PubMed: 30379876
DOI: 10.1371/journal.pone.0206260

Experimental method

X-RAY DIFFRACTION (2.1 Å)