Description

IPR019794 is a Peroxidase, active site.

<p>Peroxidases are haem-containing enzymes that use hydrogen peroxide as the electron acceptor to catalyse a number of oxidative reactions. Most haem peroxidases follow the reaction scheme:<reaction>Fe³⁺+ H₂O₂-->[Fe⁴⁺=O]R' (Compound I) + H₂O</reaction> <reaction>[Fe⁴⁺=O]R' + substrate -->[Fe⁴⁺=O]R (Compound II) + oxidised substrate</reaction> <reaction>[Fe⁴⁺=O]R + substrate -->Fe³⁺+ H₂O + oxidised substrate</reaction> <p>In this mechanism, the enzyme reacts with one equivalent of H₂O₂to give [Fe⁴⁺=O]R' (compound I). This is a two-electron oxidation/reduction reaction where H₂O₂is reduced to water and the enzyme is oxidised. One oxidising equivalent resides on iron, giving the oxyferryl [[cite:PUB00001259]] intermediate, while in many peroxidases the porphyrin (R) is oxidised to the porphyrin pi-cation radical (R'). Compound I then oxidises an organic substrate to give a substrate radical [[cite:PUB00005246]].</p> <p>Haem peroxidases include two superfamilies: one found in bacteria, fungi, plants and the second found in animals. The first one can be viewed as consisting of 3 major classes. Class I, the intracellular peroxidases, includes: yeast cytochrome c peroxidase (CCP), a soluble protein found in the mitochondrial electron transport chain, where it probably protects against toxic peroxides; ascorbate peroxidase (AP), the main enzyme responsible for hydrogen peroxide removal in chloroplasts and cytosol of higher plants; and bacterial catalase- peroxidases, exhibiting both peroxidase and catalase activities. It is thought that catalase-peroxidase provides protection to cells under oxidative stress [[cite:PUB00000617]].</p> <p>Class II consists of secretory fungal peroxidases: ligninases, or lignin peroxidases (LiPs), and manganese-dependent peroxidases (MnPs). These are monomeric glycoproteins involved in the degradation of lignin. In MnP, Mn²⁺serves as the reducing substrate [[cite:PUB00001743]]. Class II proteins contain four conserved disulphide bridges and two conserved calcium-binding sites.</p> <p>Class III consists of the secretory plant peroxidases, which have multiple tissue-specific functions: e.g., removal of hydrogen peroxide from chloroplasts and cytosol; oxidation of toxic compounds; biosynthesis of the cell wall; defence responses towards wounding; indole-3-acetic acid (IAA) catabolism; ethylene biosynthesis; and so on. Class III proteins are also monomeric glycoproteins, containing four conserved disulphide bridges and two calcium ions, although the placement of the disulphides differs from class II enzymes.</p> <p>This entry represents an active site found in a number of peroxidases.</p>

This description is obtained from EB-eye REST.

Associated GO terms

GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on April 27, 2020, while the GO metadata was last updated on April 27, 2020.

Associated Lotus transcripts 124