Enzyme - Formate C-acetyltransferase

Alternative Name(s)
  • Pyruvate formate-lyase.

Catalytic Activity

yl-CoA + formate = CoA + pyruvate


There are no Cofactors for this Enzyme

Reaction Mechanism

    Pyruvate formate-lyase catlayses the CoA-dependent, reversible cleavage of pyruvate into acetyal-CoA and formation. This enzyme is required for anaerobic glucose fermentation, utilised by various species of microorganism.

    The resting state of this enzyme has a glycyl radical, this radical is created by the action of a radical SAM superfamily activating protein (PFL-AE) and is quenched in an oxygenated atmosphere leading to enzyme inactivation.

    The resting state of the enzyme involves the glycyl radical, as determined by spectroscopic studies. The backbone radical is kinetically stable, but extremely susceptible to reactions with molecular oxygen. This is thought to be involved in regulating the enzymes function within the anaerobic metabolism, and the regulation of the pathway more generally.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    Cys P09373 419 2pfl 418
    Cys P09373 420 2pfl 419
    Trp P09373 334 2pfl 333
    Gly P09373 735 2pfl 734
    Step Components

    hydrogen relay, overall reactant used, overall product formed, enzyme-substrate complex formation, bimolecular homolytic substitution, bimolecular homolytic addition, hydrogen transfer, intermediate formation, unimolecular homolytic elimination, intermediate terminated, native state of enzyme regenerated, intermediate collapse, radical propagation, enzyme-substrate complex cleavage

    Step 1.

    The glycyl radical abstracts a hydrogen from Cys419, which in turn abstracts a hydrogen from Cys418.

    Step 2.

    Cys418 initiates a homolytic attack on the carbonyl carbon of the pyruvate substrate in an addition reaction.

    Step 3.

    The newly formed radical collapses, eliminating a carbon dioxyl radical.

    Step 4.

    The carbon dioxyl radical abstracts a hydrogen from Cys419 forming the formate product.

    Step 5.

    Cys419 abstracts a hydrogen from CoA.

    Step 6.

    CoA initiates a homolytic attack upon the carbonyl carbon of the acyl-Cys418 in a substitution reaction, eliminating Cys418, which abstracts a hydrogen from Cys419.

    Step 7.

    Cys419 abstracts a hydrogen from Gly734, regenerating the glycyl radical ground state.


    The products of the reaction.

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
Formate acetyltransferase 1 Escherichia coli (strain K12)
Formate acetyltransferase Lactococcus lactis subsp. lactis (strain IL1403)
PFL-like enzyme TdcE Escherichia coli (strain K12)
Pyruvate formate lyase Bifidobacterium magnum
Formate acetyltransferase 3, putative Streptococcus sanguinis (strain SK36)