TY - JOUR
T1 - Uncovering novel biochemistry in the mechanism of tryptophan tryptophylquinone cofactor biosynthesis
AU - Wilmot, Carrie M.
AU - Davidson, Victor L.
N1 - Funding Information:
This work was supported by National Institutes of Health Grants GM-66569 (CMW) and GM-41574 (VLD).
PY - 2009/10
Y1 - 2009/10
N2 - Catalytic quinone cofactors derived from post-translational modification of amino acid residues within the enzyme polypeptide have roles in a variety of biological processes ranging from metabolism in bacteria to inflammation and connective tissue maturation in humans. In recent years, studies of the biosynthesis of one of these cofactors, tryptophan tryptophylquinone (TTQ), have provided examples of novel chemistry that is required for the generation of these protein-derived cofactors. A novel c-type diheme enzyme, MauG, catalyzes a six-electron oxidation that completes TTQ biosynthesis in a 119-kDa protein substrate. The post-translational modification reactions proceed via an unprecedented Fe(V) equivalent catalytic intermediate comprising two hemes; one an Fe(IV){double bond, long}O and the other a six-coordinate Fe(IV) with axial ligands provided by amino acid residues. This high-valent diheme species is an alternative to Compound I, an Fe(IV){double bond, long}O heme with a porphyrin or amino acid cation radical, which is typically the reactive intermediate of heme-dependent oxygenases and peroxidases.
AB - Catalytic quinone cofactors derived from post-translational modification of amino acid residues within the enzyme polypeptide have roles in a variety of biological processes ranging from metabolism in bacteria to inflammation and connective tissue maturation in humans. In recent years, studies of the biosynthesis of one of these cofactors, tryptophan tryptophylquinone (TTQ), have provided examples of novel chemistry that is required for the generation of these protein-derived cofactors. A novel c-type diheme enzyme, MauG, catalyzes a six-electron oxidation that completes TTQ biosynthesis in a 119-kDa protein substrate. The post-translational modification reactions proceed via an unprecedented Fe(V) equivalent catalytic intermediate comprising two hemes; one an Fe(IV){double bond, long}O and the other a six-coordinate Fe(IV) with axial ligands provided by amino acid residues. This high-valent diheme species is an alternative to Compound I, an Fe(IV){double bond, long}O heme with a porphyrin or amino acid cation radical, which is typically the reactive intermediate of heme-dependent oxygenases and peroxidases.
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U2 - 10.1016/j.cbpa.2009.06.026
DO - 10.1016/j.cbpa.2009.06.026
M3 - Review article
C2 - 19648051
AN - SCOPUS:70349083704
SN - 1367-5931
VL - 13
SP - 469
EP - 474
JO - Current opinion in chemical biology
JF - Current opinion in chemical biology
IS - 4
ER -