|PROSITE documentation PDOC51405|
Heme haloperoxidase or chloroperoxidase (CPO) is an ~250 residue heme-containing glycoprotein that is secreted by various fungi. CPO was first identified in Caldariomyces fumago where it catalyzes the hydrogen peroxide-dependent chlorination of cyclopentanedione during the biosynthesis of the antibiotic caldarioymcin. Additionally, heme haloperoxidase catalyzes the iodination and bromination of a wide range of substrates. Besides performing H2O2-dependent halogenation reactions, the enzyme catalyzes dehydrogenation reactions. CPO also functions as a catalase, facilitating the decomposition of hydrogen peroxide to oxygen and water. Furthermore, heme haloperoxidase catalyzes P450-like oxygen insertion reactions. The capability of heme haloperoxidase to perform these diverse reactions makes it one of the most versatile of all known heme proteins [1,2].
Despite functional similarities with other heme enzymes, heme haloperoxidase folds into a novel tertiary structure dominated by eight helical segments (see <PDB: 1CPO>) . Structurally, heme haloperoxidase is unique, but it shares features with both peroxidases and P450 enzymes. As in cytochrome P450 enzymes, the proximal heme ligand of the heme haloperoxidase is a cysteine, but similar to peroxidases, the distal side of the heme is polar. However, unlike other peroxidases, the normally conserved distal arginine is lacking and the catalytic acid base is a glutamic acid and not a histidine .
The profile we developed covers the whole conserved region of the heme haloperoxidase family.Last update:
September 2008 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Hofrichter M. Ullrich R.|
|Title||Heme-thiolate haloperoxidases: versatile biocatalysts with biotechnological and environmental significance.|
|Source||Appl. Microbiol. Biotechnol. 71:276-288(2006).|
|2||Authors||Manoj K.M. Hager L.P.|
|Title||Chloroperoxidase, a janus enzyme.|
|3||Authors||Sundaramoorthy M. Terner J. Poulos T.L.|
|Title||The crystal structure of chloroperoxidase: a heme peroxidase--cytochrome P450 functional hybrid.|
|4||Authors||Kuhnel K. Blankenfeldt W. Terner J. Schlichting I.|
|Title||Crystal structures of chloroperoxidase with its bound substrates and complexed with formate, acetate, and nitrate.|
|Source||J. Biol. Chem. 281:23990-23998(2006).|