The enzyme catalyzes the conversion of tyrosine to dihydroxyphenylalanine. It is a homotetramer and each subunits binds a catalytic iron (PMID9228951).
DETAILS ON METAL
FE 501 x |
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| The eukaryotic enzyme requires one iron atom per subunit for activity. When isolated, the iron is typically in the ferric state, while the active form is ferrous. The C. violaceum enzyme has been isolated with copper instead of iron, and this observation led to the proposal that the bacterial enzyme does not require any metal for activity (PMID 14640675). |
| Site type | Physiological Metal |
| mononuclear | iron |
| Metal in the Resting State | |||
| Oxidation State |
Coordination Geometry | Coordination Number | PDB |
| 2 | octahedral | 6 | 1toh |
| Metal in the reaction stages | ||||||
| Step | Metal function(s) | Initial-Final Oxid. states | Initial-Final Geometry | Initial-Final Coord. # | Initial PDB | Final PDB |
| Step 1 | Coordinates substrate One electron donor |
+2 - +3 |
octahedral - octahedral |
6 - 6 | - | - |
| Step 2 | Coordinates substrate One electron acceptor |
+3 - +2 |
octahedral - octahedral |
6 - 6 | - | - |
| Step 3 | Coordinates substrate Electron pair donor |
+2 - +4 |
octahedral - octahedral |
6 - 6 | - | - |
| Step 4 | Coordinates substrate Electron pair acceptor |
+4 - +2 |
octahedral - octahedral |
6 - 6 | - | - |
| Step 5 | Coordinates substrate |
+2 - +2 |
octahedral - octahedral |
6 - 6 | - | - |
| Step 6 | Not active |
+2 - +2 |
octahedral - octahedral |
6 - 6 | - | - |
* N.B. There may be steps that are not described in between two annotated steps. Consequently the product species of step n may differ from the reagent species of step n+1.