IUBMB Enzyme Nomenclature


Accepted name: pyrroloquinoline-quinone synthase

Reaction: 6-(2-amino-2-carboxyethyl)-7,8-dioxo-1,2,3,4,7,8-hexahydroquinoline-2,4-dicarboxylate + 3 O2 = 4,5-dioxo-1H-pyrrolo[2,3-f]quinoline-2,7,9-tricarboxylate + 2 H2O2 + 2 H2O

For diagram click here.

Other name(s): PqqC

Systematic name: 6-(2-amino-2-carboxyethyl)-7,8-dioxo-1,2,3,4,5,6,7,8-octahydroquinoline-2,4-dicarboxylate:oxygen oxidoreductase (cyclizing)

Comments: So far only a single turnover of the enzyme has been observed, and the pyrroloquinoline quinone remains bound to it. It is not yet known what releases the product in the bacterium.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 353484-42-1


1. Magnusson, O.T., Toyama, H., Saeki, M., Schwarzenbacher, R. and Klinman, J.P. The structure of a biosynthetic intermediate of pyrroloquinoline quinone (PQQ) and elucidation of the final step of PQQ biosynthesis. J. Am. Chem. Soc. 126 (2004) 5342-5343. [PMID: 15113189]

2. Magnusson, O.T., Toyama, H., Saeki, M., Rojas, A., Reed, J.C., Liddington, R.C., Klinman, J.P. and Schwarzenbacher, R. Quinone biogenesis: Structure and mechanism of PqqC, the final catalyst in the production of pyrroloquinoline quinone. Proc. Natl. Acad. Sci. USA 101 (2004) 7913-7918. [PMID: 15148379]

3. Toyama, H., Chistoserdova, L. and Lidstrom, M.E. Sequence analysis of pqq genes required for biosynthesis of pyrroloquinoline quinone in Methylobacterium extorquens AM1 and the purification of a biosynthetic intermediate. Microbiology 143 (1997) 595-602. [PMID: 9043136]

4. Toyama, H., Fukumoto, H., Saeki, M., Matsushita, K., Adachi, O. and Lidstrom, M.E. PqqC/D, which converts a biosynthetic intermediate to pyrroloquinoline quinone. Biochem. Biophys. Res. Commun. 299 (2002) 268-272. [PMID: 1243798]

5. Schwarzenbacher, R., Stenner-Liewen, F., Liewen, H., Reed, J.C. and Liddington, R.C. Crystal structure of PqqC from Klebsiella pneumoniae at 2.1 Å resolution. Protein 56 (2004) 401-403. [PMID: 15211525]

[EC created 2005]

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