3IXF | pdb_00003ixf

Structure of dehaloperoxidase B at 1.58 A resolution and structural characterization of the AB dimer from Amphitrite ornata.

(2010) Acta Crystallogr D Biol Crystallogr 66: 529-538

• PubMed: 20445228 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1107/S0907444910004580
• Primary Citation of Related Structures:  
  3IXF


• PubMed Abstract: 
  

  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 A 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(2)O(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.

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Organizational Affiliation: 

North Carolina State University, USA.