Pyrroloquinoline-quinone synthase

In enzymology, a pyrroloquinoline-quinone synthase (EC 1.3.3.11) is an enzyme that catalyzes the chemical reaction

6-(2-amino-2-carboxyethyl)-7,8-dioxo-1,2,3,4,5,6,7,8-octahydroquinoline-2,4-dicarboxylate + 3 O₂ 4,5-dioxo-3a,4,5,6,7,8,9,9b-octahydro-1H-pyrrolo[2,3-f]quinoline- 2,7,9-tricarboxylate + 2 H₂O₂ + 2 H₂O

The two substrates of this enzyme are 6-(2-amino-2-carboxyethyl)-7,8-dioxo-1,2,3,4,5,6,7,8-octahydroquinoline-2,4-dicarboxylate, and O₂, whereas its 3 products are 4,5-dioxo-3a,4,5,6,7,8,9,9b-octahydro-1H-pyrrolo[2,3-f]quinoline-2,7,9-tricarboxylate, H₂O₂, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with oxygen as acceptor. The systematic name of this enzyme class is 6-(2-amino-2-carboxyethyl)-7,8-dioxo-1,2,3,4,5,6,7,8-octahydroquinol ine-2,4-dicarboxylate:oxygen oxidoreductase (cyclizing). This enzyme is also called PqqC.

References

• Magnusson OT, Toyama H, Saeki M, Schwarzenbacher R, Klinman JP (2004). "The structure of a biosynthetic intermediate of pyrroloquinoline quinone (PQQ) and elucidation of the final step of PQQ biosynthesis". J. Am. Chem. Soc. 126 (17): 5342–3. doi:10.1021/ja0493852. PMID 15113189. 
• Klinman JP, Schwarzenbacher R (2004). "Quinone biogenesis: Structure and mechanism of PqqC, the final catalyst in the production of pyrroloquinoline quinone". Proc. Natl. Acad. Sci. U.S.A. 101 (21): 7913–8. doi:10.1073/pnas.0402640101. PMC 419531. PMID 15148379. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=419531. 
• Toyama H, Chistoserdova L, Lidstrom ME (Pt 2). "Sequence analysis of pqq genes required for biosynthesis of pyrroloquinoline quinone in Methylobacterium extorquens AM1 and the purification of a biosynthetic intermediate". Microbiology. 143 (2): 595–602. doi:10.1099/00221287-143-2-595. PMID 9043136. 
• Yasunaga K (1975). "[Concept of thrombocytopathy and problems involved in its diagnosis (author's transl)]". Nippon. Ketsueki. Gakkai. Zasshi. 38 (6): 734–40. PMID 1243798. 
• RC; Stenner-Liewen, F; Liewen, H; Reed, JC; Liddington, RC (2004). "Crystal structure of PqqC from Klebsiella pneumoniae at 2.1 A resolution". Proteins. 56 (2): 401–3. doi:10.1002/prot.20085. PMID 15211525.