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Entry M0122    1.8.4.11    protein-methionine-S-oxide reductase

Next Step

Step 01

Cys72 initiates a nucleophilic attack on the sulfoxide in an addition reaction with concomitant deprotonation of Glu115.

GIF of Reaction Step M0122.stg01


Comment: Cys72 is activated and stabilised as a thiolate anion due to its location at the positive end of the alpha1 helix dipole [2].



Mechanisms

Bimolecular Nucleophilic Addition
Proton Transfer

Mechanism Components

Overall Reactant Used
Bond Formation
Enzyme-Substrate Bond Formation
Bond Cleavage
Bond Order Change
Intermediate Formation

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Tyr155 Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Glu115 Side Chain reactant Hydrogen Bond Donor
Proton Donor
Tyr103 Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Cys72 Side Chain reactant Nucleophile
Cys218 Side Chain spectator Not Active
Cys227 Side Chain spectator Not Active

Reactive Centre

Bonds Formed Bonds Cleaved Bonds Changed in Order Atom Types Involved
O-H
S-S
O-H
The S-O bond changes from a double to single bond
H
O
S

View similar reactions in MACiE.


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