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Catalytic Site Atlas Search Results
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Catalytic Site Atlas

CSA LITERATURE entry for 1oxa

E.C. nameCYTOCHROME P450 ERYF
SpeciesSaccharopolyspora erythraea (strain NRRL 23338)
E.C. Number (IntEnz) 1.-.-.-
CSA Homologues of 1oxa
CSA Entries With UniProtID
CSA Entries With EC Number 1.-.-.-
PDBe Entry 1oxa
PDBSum Entry 1oxa
MACiE Entry 1oxa

Literature Report

IntroductionCytochromes P450, a gene superfamily of heme proteins found in all eukaryotes, most prokaryotes, and Archaea, catalyze 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 a step in erythromycin sythesis, 6S-deoxyerythronolide B (6-DEB) hydroxylation.
MechansimThe catalytic cycle of all cytochrome P450s is conserved. Electrons are delivered to the haem centre by NADH, permitting oxygen reduction.
Binding of the substrate promotes electron transfer to P450 haem, reducing the iron from Fe(III) to Fe(II). Dioxygen binds and thus Fe(II) is oxidised back to Fe(III). A second electron is passed to the haem forming a superoxide species, followed by donation of two protons. Catalytic water (Wat564), and uniquely the C5 hydroxyl group of 6-DEB, provide the protons to the distil oxygen. This results in the loss of water and the formation of the low spin Fe(IV) oxo complex.
Reprotonation of the catalytic water and 6-DEB after protonation of dioxygen occurs via a hydrogen bonded network presumed to be in contact with the bulk solvent during the course of the reaction.
The rebound mechanism forms the alcohol group on the substrate once the oxo group is formed. The Fe(IV)-oxo complex undergoes spin inversion to form a radical oxo group which removes a hydrogen from the substrate to form a radical carbon centre and an alcohol group on Fe(IV). The new radical then attacks the oxygen to form the alcohol group and Fe(III), completing the catalytic cycle.

Catalytic Sites for 1oxa

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
GluA360360macie:sideChainMember of the hydrogen bonded network which replenishes the protons in the active site.
SerA246246macie:sideChainMember of the hydrogen bonded network which replenishes the protons in the active site.

Literature References

Notes:Although there is a water (Wat519) bound close to the active site in this structure, the dioxygen bound structure (PDB code 1jio) shows that it is displaced by dioxygen binding.
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