Structure of dehaloperoxidase B at 1.58 Å resolution and structural characterization of the AB dimer from Amphitrite ornata
The crystal structure of dehaloperoxidase (DHP) isoenzyme B from the terebellid polychaete A. ornata, which exhibits both hemoglobin and peroxidase functions, has been determined at 1.58 Å resolution. As members of the globin superfamily, dehaloperoxidase (DHP) isoenzymes A and B from the marine annelid Amphitrite ornata possess hemoglobin function, but they also exhibit a biologically relevant peroxidase activity that is capable of converting 2,4,6-trihalophenols to the corresponding 2,6-dihaloquinones in the presence of hydrogen peroxide. Here, a comprehensive structural study of recombinant DHP B, both by itself and cocrystallized with isoenzyme A, using X-ray diffraction is presented. The structure of DHP B refined to 1.58 Å resolution exhibits the same distal histidine (His55) conformational flexibility as that observed in isoenzyme A, as well as additional changes to the distal and proximal hydrogen-bonding networks. Furthermore, preliminary characterization of the DHP AB heterodimer is presented, which exhibits differences in the AB interface that are not observed in the A-only or B-only homodimers. These structural investigations of DHP B provide insights that may relate to the mechanistic details of the H{sub 2}O{sub 2}-dependent oxidative dehalogenation reaction catalyzed by dehaloperoxidase, present a clearer description of the function of specific residues in DHP at the molecular level and lead to a better understanding of the paradigms of globin structure–function relationships.
- OSTI ID:
- 22351204
- Journal Information:
- Acta Crystallographica. Section D: Biological Crystallography, Vol. 66, Issue Pt 5; Other Information: PMCID: PMC2865366; PMID: 20445228; PUBLISHER-ID: hm5083; OAI: oai:pubmedcentral.nih.gov:2865366; Copyright (c) International Union of Crystallography 2010; Country of input: International Atomic Energy Agency (IAEA); ISSN 0907-4449
- Country of Publication:
- Denmark
- Language:
- English
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