Structural insights into substrate recognition of tri-modular xyloglucanase from Aspergillus oryzae.
Nakamichi, Y., Shimada, N., Watanabe, M., Fujii, T., Yaoi, K., Matsuzawa, T.(2025) J Struct Biol 217: 108213-108213
- PubMed: 40414580 
- DOI: https://doi.org/10.1016/j.jsb.2025.108213
- Primary Citation of Related Structures:  
9L3D, 9L3J, 9L3O, 9L3P - PubMed Abstract: 
Xeg5A from Aspergillus oryzae belongs to glycoside hydrolase family 5 subfamily 4. This enzyme has been characterized as a xyloglucan-specific endo-β-1,4-glucanase (xyloglucanase) that cleaves the main chain of xyloglucan at both unbranched and xylosylated glucosyl residues in an endo-processive mode of action. X-ray crystallography revealed that Xeg5A is a tri-modular enzyme composed of a catalytic, an Ig-like, and a C-terminal CBM46-like domains. Xeg5A structures complexed with branched xyloglucan oligosaccharides at subsites -4 to +4 showed that the recognition of xyloglucan side-chain moieties is important for Xeg5A activity. The crystal structure also provided structural insights into the role of the CBM46-like domain in contributing to regiospecificity and, possibly, processivity.
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
Organizational Affiliation: