Entry M0133    camphor 5-monooxygenase

Next Step

Step 01

Putidaredoxin donates a single electron to the Fe(III) centre of the heme cofactor.

GIF of Reaction Step M0133.stg01

Comment: The low-spin resting state, which is unusual in a ferric-aquo-heme complex, could be explained by means of the axial ligands. Antibonding interactions of the iron with the axial ligands (Cys357 and a water molecule) stabilise the doublet with respect to the quartet and sextet states. When camphor binds, it displaces the axial water ligand and an inversion of the spin state is observed. The stabilisation of the high-spin state could be explained by electrostatic interactions of the protein with the cysteine sulfur decreasing the spin density in the sulfur atom for all the spin states. Such effect is caused by hydrogen bonds from Gly359 and Leu358 to the sulfur [1].


Electron Transfer
Elimination Reaction

Mechanism Components

Overall Reactant Used
Cofactor Used
Bond Cleavage
Metal De-coordination
Intermediate Formation

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Arg186 Side Chain spectator Hydrogen Bond Donor
Asp251 Side Chain spectator Hydrogen Bond Donor
Hydrogen Bond Acceptor
Thr252 Side Chain spectator Hydrogen Bond Acceptor
Hydrogen Bond Donor
Cys357 Side Chain spectator Metal Ligand
Electrostatic Stabiliser
Hydrogen Bond Acceptor
Leu358 Main Chain Amide spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Gly359 Main Chain Amide spectator Hydrogen Bond Donor
Electrostatic Stabiliser

Metal Cofactors involved in Step 01

Metal Type Metal Identity Chain Activity Function
iron HEM 417 A reactant One Electron Acceptor

Reactive Centre

Bonds Formed Bonds Cleaved Bonds Changed in Order Atom Types Involved

View similar reactions in MACiE.