spacer

Entry M0028    3.1.4.11    phosphoinositide phospholipase C

Next Step

Step 01

Glu390 deprotonates the hydroxyl group adjacent to the phosphate, which initiates a nucleophilic attack on the phosphorus in a substitution reaction that eliminates diacylglycerol which deprotonates His356.

GIF of Reaction Step M0028.stg01


Comment: Glu390 is tentatively identified as general base. Glu341 is also a possibility, His311 ruled out on account of it not being hydrogen-bonded to the substrate. The reaction proceeds through a pentavalent phosphate transition state.



Mechanisms

Proton Transfer
Intramolecular Nucleophilic Substitution

Mechanism Components

Bond Cleavage
Bond Formation
Overall Reactant Used
Overall Product Formed
Cyclisation
Intermediate Formation

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Asn312 Side Chain spectator Electrostatic Stabiliser
Hydrogen Bond Donor
Metal Ligand
His356 Side Chain reactant Hydrogen Bond Donor
Proton Donor
Glu390 Side Chain reactant Metal Ligand
Proton Acceptor
Hydrogen Bond Acceptor
His311 Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser

Metal Cofactors involved in Step 01

Metal Type Metal Identity Chain Activity Function
calcium CA 2 A spectator Substrate Binding
Electrostatic Stabiliser
Increase Electrophilicity
Activator

Reactive Centre

Bonds Formed Bonds Cleaved Bonds Changed in Order Atom Types Involved
O-H
O-H
P-O
N-H
O-H
P-O
None
H
N
O
P

View similar reactions in MACiE.


spacer
spacer