8IQ8
Crystal structure of 3,4-dihydroxyphenylacetate 2,3-dioxygenase (DHPAO) from Acinetobacter baumannii
Summary for 8IQ8
| Entry DOI | 10.2210/pdb8iq8/pdb |
| Descriptor | 3,4-dihydroxyphenylacetate 2,3-dioxygenase, SODIUM ION (3 entities in total) |
| Functional Keywords | extradiol dioxygenase, oxidoreductase |
| Biological source | Acinetobacter baumannii |
| Total number of polymer chains | 4 |
| Total formula weight | 129618.84 |
| Authors | |
| Primary citation | Pimviriyakul, P.,Buttranon, S.,Soithongcharoen, S.,Supawatkon, C.,Disayabootr, K.,Watthaisong, P.,Tinikul, R.,Jaruwat, A.,Chaiyen, P.,Chitnumsub, P.,Maenpuen, S. Structure and biochemical characterization of an extradiol 3,4-dihydroxyphenylacetate 2,3-dioxygenase from Acinetobacter baumannii. Arch.Biochem.Biophys., 747:109768-109768, 2023 Cited by PubMed Abstract: 3,4-Dihydroxyphenylacetate (DHPA) 2,3-dioxygenase (EC 1.13.11.15) from Acinetobacter baumannii (AbDHPAO) is an enzyme that catalyzes the 2,3-extradiol ring-cleavage of DHPA in the p-hydroxyphenylacetate (HPA) degradation pathway. While the biochemical reactions of various DHPAOs have been reported, only structures of DHPAO from Brevibacterium fuscum and their homologs are available. Here, we report the X-ray structure and biochemical characterization of an Fe-specific AbDHPAO that shares 12% sequence identity to the enzyme from B. fuscum. The 1.8 Å X-ray structure of apo-AbDHPAO was determined with four subunits per asymmetric unit, consistent with a homotetrameric structure. Interestingly, the αβ-sandwiched fold of the AbDHPAO subunit is different from the dual β-barrel-like motif of the well-characterized B. fuscum DHPAO structures; instead, it is similar to the structures of non-DHPA extradiol dioxygenases from Comamonas sp. and Sphingomonas paucimobilis. Similarly, these extradiol dioxygenases share the same chemistry owing to a conserved 2-His-1-carboxylate catalytic motif. Structure analysis and molecular docking suggested that the Fe cofactor and substrate binding sites consist of the conserved residues His12, His57, and Glu238 forming a 2-His-1-carboxylate motif ligating to Fe and DHPA bound with Fe in an octahedral coordination. In addition to DHPA, AbDHPAO can also use other 3,4-dihydroxyphenylacetate derivatives with different aliphatic carboxylic acid substituents as substrates, albeit with low reactivity. Altogether, this report provides a better understanding of the structure and biochemical properties of AbDHPAO and its homologs, which is advancing further modification of DHPAO in future applications. PubMed: 37769893DOI: 10.1016/j.abb.2023.109768 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
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