8K04

CryoEM structure of a 2,3-hydroxycinnamic acid 1,2-dioxygenase MhpB in apo form

Summary for 8K04

• Entry DOI: 10.2210/pdb8k04/pdb
• EMDB information: 36757
• Descriptor: 2,3-dihydroxyphenylpropionate/2,3-dihydroxicinnamic acid 1,2-dioxygenase (1 entity in total)
• Functional Keywords: dioxygenase, biosynthetic protein
• Biological source: Escherichia coli
• Total number of polymer chains: 10
• Total formula weight: 342309.61

Authors

Jiang, W.X.,Cheng, X.Q.,Ma, L.X.,Xing, Q. (deposition date: 2023-07-07, release date: 2024-07-10, Last modification date: 2025-02-12)

Primary citation

Dong, X.,Xu, M.,Wu, M.,Wang, Y.,Cheng, X.,Jiang, W.,Zheng, D.,Omar, A.H.,Cheng, Y.,Li, A.,Ma, L.,Xing, Q.
Structural and catalytic insights into MhpB: A dioxygenase enzyme for degrading catecholic pollutants.
J Hazard Mater, 488:137431-137431, 2025

PubMed Abstract: The increasing environmental pollution from persistent aromatic compounds requires effective biodegradation strategies. In this study, we focused on MhpB, an extradiol dioxygenase (EDO) from Escherichia coli. It is known for its role in the degradation of catechols, key intermediates in the degradation of aromatic compounds. We report the high-resolution structure of MhpB determined by cryo-electron microscopy, revealing a decameric conformation with the catalytic chamber at the side. The structure-based analysis allowed us to investigate the substrate-enzyme interaction and the substrate selectivity, which are crucial for its catalytic function. Site-directed mutagenesis was used to modulate the in vitro and in vivo substrate preference of MhpB, enhancing its potential for industrial applications in pollutant degradation. The study provides insight into the mechanism of the enzyme and paves the way for the development of engineered EDOs for environmental remediation of aromatic pollutants.

PubMed: 39892151
DOI: 10.1016/j.jhazmat.2025.137431

Experimental method

ELECTRON MICROSCOPY (2.72 Å)