4HUZ

2,6-Dichloro-p-hydroquinone 1,2-Dioxygenase

Summary for 4HUZ

• Entry DOI: 10.2210/pdb4huz/pdb
• Descriptor: 2,6-dichloro-p-hydroquinone 1,2-dioxygenase, FE (III) ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: oxidoreductase
• Biological source: Sphingobium chlorophenolicum
• Total number of polymer chains: 1
• Total formula weight: 36713.58

Authors

Hayes, R.P.,Nissen, M.S.,Green, A.R.,Lewis, K.M.,Xun, L.,Kang, C. (deposition date: 2012-11-05, release date: 2013-04-17, Last modification date: 2023-09-20)

Primary citation

Hayes, R.P.,Green, A.R.,Nissen, M.S.,Lewis, K.M.,Xun, L.,Kang, C.
Structural characterization of 2,6-dichloro-p-hydroquinone 1,2-dioxygenase (PcpA) from Sphingobium chlorophenolicum, a new type of aromatic ring-cleavage enzyme.
Mol.Microbiol., 88:523-536, 2013

PubMed Abstract: PcpA (2,6-dichloro-p-hydroquinone 1,2-dioxygenase) from Sphingobium chlorophenolicum, a non-haem Fe(II) dioxygenase capable of cleaving the aromatic ring of p-hydroquinone and its substituted variants, is a member of the recently discovered p-hydroquinone 1,2-dioxygenases. Here we report the 2.6 Å structure of PcpA, which consists of four βαβββ motifs, a hallmark of the vicinal oxygen chelate superfamily. The secondary co-ordination sphere of the Fe(II) centre forms an extensive hydrogen-bonding network with three solvent exposed residues, linking the catalytic Fe(II) to solvent. A tight hydrophobic pocket provides p-hydroquinones access to the Fe(II) centre. The p-hydroxyl group is essential for the substrate-binding, thus phenols and catechols, lacking a p-hydroxyl group, do not bind to PcpA. Site-directed mutagenesis and kinetic analysis confirm the critical catalytic role played by the highly conserved His10, Thr13, His226 and Arg259. Based on these results, we propose a general reaction mechanism for p-hydroquinone 1,2-dioxygenases.

PubMed: 23489289
DOI: 10.1111/mmi.12204

Experimental method

X-RAY DIFFRACTION (2.6 Å)