|PROSITE documentation PDOC00394|
Heme-binding peroxidases (EC 1.11.1.-)  carry out a variety of biosynthetic and degradative functions using hydrogen peroxide as the electron acceptor. The heme prosthetic group is protoporphyrin IX and the fifth ligand of the heme iron is a histidine (known as the proximal histidine). An other histidine residue (the distal histidine) serves as an acid-base catalyst in the reaction between hydrogen peroxide and the enzyme. The regions around these two active site residues are more or less conserved in a majority of peroxidases [2,3].
Heme peroxidases are widely distributed throughout bacteria, fungi, plants, and vertebrates. On the basis of structural properties they can be devided in two large superfamilies.
The plant peroxidase superfamily (can be grouped in three classes):
Class I. Peroxidase of prokaryotic origin: - Plant ascorbate peroxidases. They play a key role in hydrogen peroxide removal in the chloroplasts and cytosol of higher plants. - Yeast cytochrome c peroxidase (EC 22.214.171.124). - Prokaryotic catalase-peroxidases. Some bacterial species produce enzymes that exhibit both catalase and broad-spectrum peroxidase activities . Examples of such enzymes are: catalase HP I from Escherichia coli (gene katG) and perA from Bacillus stearothermophilus. Class II. Secreted fungal peroxidases: - Fungal ligninases. Ligninase catalyzes the first step in the degradation of lignin. It depolymerizes lignin by catalyzing the C(alpha)-C(beta) cleavage of the propyl side chains of lignin. Class III. Classical secretory plant peroxidases: - Plant peroxidases (EC 126.96.36.199). Plants express a large number of isozymes of peroxidases. Some of them play a role in cell-suberization by catalyzing the deposition of the aromatic residues of suberin on the cell wall, some are expressed as a defense response toward wounding, others are involved in the metabolism of auxin and the biosynthesis of lignin.
The animal peroxidase superfamily:
The two patterns we developed recognize both superfamilies. Our first pattern recognizes the proximal heme-binding site whereas the second pattern surrounded the distal active site. We also developed two profiles, one specific for the animal peroxidases superfamily and one directed against the plant peroxidase superfamily.Last update:
April 2006 / Pattern revised.
PROSITE methods (with tools and information) covered by this documentation:
|Title||Probing structure-function relations in heme-containing oxygenases and peroxidases.|
|2||Authors||Kimura S., Ikeda-Saito M.|
|Title||Human myeloperoxidase and thyroid peroxidase, two enzymes with separate and distinct physiological functions, are evolutionarily related members of the same gene family.|
|3||Authors||Henrissat B., Saloheimo M., Lavaitte S., Knowles J.K.C.|
|Title||Structural homology among the peroxidase enzyme family revealed by hydrophobic cluster analysis.|
|Title||Bacterial catalase-peroxidases are gene duplicated members of the plant peroxidase superfamily.|
|Source||Biochim. Biophys. Acta 1080:215-220(1991).|