spacer

Entry M0262    4.2.3.6    trichodiene synthase

Previous Step     Next Step

Step 03

Intramolecular elimination of the pyrophosphate.

GIF of Reaction Step M0262.stg03


Comment: Free rotation about the C2-C3 bond from the transoid to cisoid conformation orientates the empty p orbital of C1 in the cation towards the C6-C7 pi orbital to facilitate the C1-C6 bond formation. It is currently unclear is this is concomitant with, or prior to the dipohsphate departure [1]. The positive charge of carbo cation delocalised over the three terminal carbon atoms. It is likely that the phosphate remains bound and aids in electrostatic stabilisation of the reaction intermediates [1].



Mechanisms

Intramolecular Elimination

Mechanism Components

Bond Cleavage
Bond Order Change
Charge Delocalisation
Intermediate Formation

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Tyr93 Side Chain spectator van der Waals interaction
Leu97 Side Chain spectator van der Waals interaction
Thr96 Side Chain spectator van der Waals interaction
Asp100 Side Chain spectator Metal Ligand
Electrostatic Stabiliser
Arg182 Side Chain spectator Electrostatic Stabiliser
Promotes Heterolytic Reactions
Hydrogen Bond Donor
Lys232 Side Chain spectator Electrostatic Stabiliser
Promotes Heterolytic Reactions
Hydrogen Bond Donor
Arg304 Side Chain spectator Electrostatic Stabiliser
Promotes Heterolytic Reactions
Hydrogen Bond Donor
Tyr305 Side Chain spectator Promotes Heterolytic Reactions
Electrostatic Stabiliser
Hydrogen Bond Donor

Metal Cofactors involved in Step 03

Metal Type Metal Identity Chain Activity Function
magnesium MG 701 B spectator Substrate Binding
Activator
Promotes Heterolytic Reactions
Electrostatic Stabiliser
magnesium MG 702 B spectator Substrate Binding
Activator
Promotes Heterolytic Reactions
Electrostatic Stabiliser
magnesium MG 703 B spectator Substrate Binding
Activator
Promotes Heterolytic Reactions
Electrostatic Stabiliser

Reactive Centre

Bonds Formed Bonds Cleaved Bonds Changed in Order Atom Types Involved
None
C-O
The C-C bond changes from a single to double bond
The C-C bond changes from a double to single bond
C
O

View similar reactions in MACiE.


spacer
spacer