Structure of dehaloperoxidase B at 1.58 Å resolution and structural characterization of the AB dimer from Amphitrite ornata
- NCSU
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 {angstrom} 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.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- UNIVERSITYNIHU.S. ARMY RESEARCH
- OSTI ID:
- 1033803
- Journal Information:
- Acta Crystallogr. D, Vol. 66, Issue (5) ; 05, 2010; ISSN 0907-4449
- Country of Publication:
- United States
- Language:
- ENGLISH
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