Cytochrome P450s are haem-thiolate proteins [6] involved in the oxidative degradation of various compounds. They are particularly well known for their role in the degradation of environmental toxins and mutagens. They can be divided into 4 classes, a ...
Cytochrome P450s are haem-thiolate proteins [6] involved in the oxidative degradation of various compounds. They are particularly well known for their role in the degradation of environmental toxins and mutagens. They can be divided into 4 classes, according to the method by which electrons from NAD(P)H are delivered to the catalytic site. Sequence conservation is relatively low within the family - there are only 3 absolutely conserved residues - but their general topography and structural fold are highly conserved. The conserved core is composed of a coil termed the 'meander', a four-helix bundle, helices J and K, and two sets of beta-sheets. These constitute the haem-binding loop (with an absolutely conserved cysteine that serves as the 5th ligand for the haem iron), the proton-transfer groove and the absolutely conserved EXXR motif in helix K. While prokaryotic P450s are soluble proteins, most eukaryotic P450s are associated with microsomal membranes. their general enzymatic function is to catalyse regiospecific and stereospecific oxidation of non-activated hydrocarbons at physiological temperatures [6].
6-deoxyerythronolide B hydroxylase (P450eryF) is a heme-thiolate protein (P-450). P-450s are a superfamily of heme proteins found in all eukaryotes, most prokaryotes, and Archaea and catalyse the monooxygenation of a wide variety of organic molecules. P450 reactions of biological significance include steroid biogenesis, drug metabolism, procarcinogen activation, xenobiotic detoxification, and fatty acid metabolism. P450eryF catalyses the NADPH-dependent conversion of 6-deoxyerythronolide B (6-DEB) to erythronolide B (EB) by the insertion of an oxygen at the 6S position of 6-DEB. Function requires the participation of a ferredoxin and a ferredoxin reductase for the transfer of electrons from NADPH to the monooxygenase.
Defined by 5 residues: ALA:A-240 [auth A-241]GLU:A-243 [auth A-244]SER:A-245 [auth A-246]CYS:A-350 [auth A-351]GLU:A-359 [auth A-360]
