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Entry M0126    1.12.2.1    cytochrome-c3 hydrogenase

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Step 03

Cys530 loses its proton to bulk solvent in which Glu18 acts as a proton relay.

GIF of Reaction Step M0126.stg03


Comment: It is possible that Glu18 acts as a proton gate, and so this de-protonation step occurs through Glu18 and thence to bulk solvent through an extended proton relay chain [1,2], alternatively, the proton may leave the active site via a water channel [4].



Mechanisms

Proton Transfer

Mechanism Components

Bond Cleavage
Bond Formation
Overall Product Formed

Amino acids involved in the reaction step.

Amino Acid Location of Function Activity Function
Arg463B Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Ser486B Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Cys530B Side Chain reactant Metal Ligand
Hydrogen Bond Donor
Proton Donor
Cys65B Side Chain spectator Metal Ligand
Activator
Cys533B Side Chain spectator Metal Ligand
Activator
Electrostatic Stabiliser
Cys68B Side Chain spectator Metal Ligand
Activator
Electrostatic Stabiliser
His72B Side Chain spectator Hydrogen Bond Donor
Electrostatic Stabiliser
Glu18B Side Chain reactant Hydrogen Bond Acceptor
Hydrogen Bond Donor
Proton Acceptor
Proton Donor
Proton Relay

Metal Cofactors involved in Step 03

Metal Type Metal Identity Chain Activity Function
iron FCO 537 L spectator
iron F3S 266 S spectator
iron SF4 265 S spectator
nickel NI 538 L spectator
iron SF4 267 S spectator

Reactive Centre

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

View similar reactions in MACiE.


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