Structural highlights
Function
MHPB_ECOLI Catalyzes the non-heme iron(II)-dependent oxidative cleavage of 2,3-dihydroxyphenylpropionic acid and 2,3-dihydroxicinnamic acid into 2-hydroxy-6-ketononadienedioate and 2-hydroxy-6-ketononatrienedioate, respectively.[1] [2]
Publication Abstract from PubMed
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.
Structural and catalytic insights into MhpB: A dioxygenase enzyme for degrading catecholic pollutants.,Dong X, Xu M, Wu M, Wang Y, Cheng X, Jiang W, Zheng D, Omar AH, Cheng Y, Li A, Ma L, Xing Q J Hazard Mater. 2025 Jan 28;488:137431. doi: 10.1016/j.jhazmat.2025.137431. PMID:39892151[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bugg TD. Overproduction, purification and properties of 2,3-dihydroxyphenylpropionate 1,2-dioxygenase from Escherichia coli. Biochim Biophys Acta. 1993 Oct 6;1202(2):258-64. PMID:8399388 doi:10.1016/0167-4838(93)90013-h
- ↑ Spence EL, Kawamukai M, Sanvoisin J, Braven H, Bugg TD. Catechol dioxygenases from Escherichia coli (MhpB) and Alcaligenes eutrophus (MpcI): sequence analysis and biochemical properties of a third family of extradiol dioxygenases. J Bacteriol. 1996 Sep;178(17):5249-56. PMID:8752345 doi:10.1128/jb.178.17.5249-5256.1996
- ↑ Dong X, Xu M, Wu M, Wang Y, Cheng X, Jiang W, Zheng D, Omar AH, Cheng Y, Li A, Ma L, Xing Q. Structural and catalytic insights into MhpB: A dioxygenase enzyme for degrading catecholic pollutants. J Hazard Mater. 2025 Jan 28;488:137431. PMID:39892151 doi:10.1016/j.jhazmat.2025.137431
