spacer

Entry M0234    6.3.5.2    GMP synthase (glutamine-hydrolysing)

Next Step

Step 01

The beta-phosphate deprotonates the XMP substrate, which then initiates a nucleophilic attack on the alpha-phosphate of ATP, eliminating pyrophosphate.

GIF of Reaction Step M0234.stg01


Comment: Reaction occurs in the ATP pyrophosphatase domain (CATH 3.40.50.620). It has been suggested that ATP and XMP bind first. It is unclear whether XMP binds in the tautomer shown, or tautomerises upon binding.



Mechanisms

Bimolecular Nucleophilic Substitution
Proton Transfer

Mechanism Components

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

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Lys381 Side Chain spectator Electrostatic Stabiliser
Hydrogen Bond Donor
Asp239 Side Chain spectator Metal Ligand
Electrostatic Stabiliser
Steric Role
Hydrogen Bond Acceptor

Metal Cofactors involved in Step 01

Metal Type Metal Identity Chain Activity Function
magnesium MG 530 B spectator Substrate Binding
Activator
Increase Electrophilicity
Electrostatic Stabiliser

Reactive Centre

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

View similar reactions in MACiE.


spacer
spacer