The idea in this group transfer reaction is to have the -OH group on the Serinf sidechain attack the substrate boune phosphate group.

-OH is not a good attacking agent for a group transfer reaction- it would be much better if it were unprotonated -O- instead.

  1. A metal ion cofactor (usually Mn2+) is near the Serine sidechain
  2. Its proximity lowers the pK of the alcohol sufficiently that it spends some time unprotonated

The results of the previous steps are shown.

  1. The unprotonated Serine sidechain attackes the phosphate
  2. As a result a pair of electrons moves onto the hydroxyl group on C3
  3. which picks up the proton and is now an alcohol

The results of the previous step is shown

  1. he phosphate is now covalently attached to the Serine.

  1. The -OH group on C2 is also near the Mn2+ so it becomes unprotontated because tof the shift in pK

The results of the previous steps are shown.

  1. The resulting -O- attacks the Serine bound phosphate
  2. A pair of electrons moves onto the oxygen which picks up the proton

the results of the previous step is shown

  1. The phosphate is on the C2 alcohol
  2. All enzyme pieces are back to their original state

Anaerobic Glucose Metabolism

Glycerate Mutase Information


Enzyme Name

Glycerate Mutase



Reaction Catalyzed

Group Transfer of phosphate from C3 to C2 of glycerate

Reaction Type

Group Transfer Reaction

Pathway Involvement

Glycolysis AND gluconeogenesis


Cofactors/Cosubstrates

Many Of these enzymes as isolated from various sources require an active site metal ion to alter the ionization of the important alcohol groups (see mechanism below).