6UQJ

Crystal structure of the GH39 enzyme from Xanthomonas axonopodis pv. citri

Summary for 6UQJ

• Entry DOI: 10.2210/pdb6uqj/pdb
• Descriptor: Beta-xylosidase (2 entities in total)
• Functional Keywords: glycoside hydrolase family 39, hydrolase
• Biological source: Xanthomonas axonopodis pv. citri (strain 306)
• Total number of polymer chains: 1
• Total formula weight: 57439.85

Authors

Morais, M.A.B.,Polo, C.C.,Santos, C.R.,Murakami, M.T. (deposition date: 2019-10-20, release date: 2020-07-22, Last modification date: 2023-10-11)

Primary citation

de Morais, M.A.B.,Polo, C.C.,Domingues, M.N.,Persinoti, G.F.,Pirolla, R.A.S.,de Souza, F.H.M.,Correa, J.B.L.,Dos Santos, C.R.,Murakami, M.T.
Exploring the Molecular Basis for Substrate Affinity and Structural Stability in Bacterial GH39 beta-Xylosidases.
Front Bioeng Biotechnol, 8:419-419, 2020

PubMed Abstract: The glycoside hydrolase family 39 (GH39) is a functionally expanding family with limited understanding about the molecular basis for substrate specificity and extremophilicity. In this work, we demonstrate the key role of the positive-subsite region in modulating substrate affinity and how the lack of a C-terminal extension impacts on oligomerization and structural stability of some GH39 members. The crystallographic and SAXS structures of a new GH39 member from the phytopathogen support the importance of an extended C-terminal to promote oligomerization as a molecular strategy to enhance thermal stability. Comparative structural analysis along with site-directed mutagenesis showed that two residues located at the positive-subsite region, Lys166 and Asp167, are critical to substrate affinity and catalytic performance, by inducing local changes in the active site for substrate binding. These findings expand the molecular understanding of the mechanisms involved in substrate recognition and structural stability of the GH39 family, which might be instrumental for biological insights, rational enzyme engineering and utilization in biorefineries.

PubMed: 32500063
DOI: 10.3389/fbioe.2020.00419

Experimental method

X-RAY DIFFRACTION (1.707 Å)