PQQ: biosynthetic studies in Methylobacterium AM1 and Hyphomicrobium X using specific 13C labeling and NMR.
Antonie Van Leeuwenhoek
; 56(1): 93-101, 1989 May.
Article
em En
| MEDLINE
| ID: mdl-2549867
ABSTRACT
Using 13C labeling and NMR spectroscopy we have determined biosynthetic precursors of pyrroloquinoline quinone (PQQ) in two closely related serine-type methylotrophs, Methylobacterium AM1 and Hyphomicrobium X. Analysis of the 13C-labeling data revealed that PQQ is constructed from two amino acids the portion containing N-6,C-7, 8, 9 and the two carboxylic acid groups, C-7' and 9', is derived-intact -from glutamate. The remaining portion is derived from tyrosine; the phenol side chain provides the six carbons of the ring containing the orthoquinone, whereas internal cyclization of the amino acid backbone forms the pyrrole-2-carboxylic acid moiety. This is analogous to the cyclization of dopaquinone to form dopachrome. Dopaquinone is a product of the oxidation of tyrosine (via dopa) in reactions catalyzed by monophenol monooxygenase (EC 1.14.18.1). Starting with tyrosine and glutamate, we will discuss possible biosynthetic routes to PQQ.
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Base de dados:
MEDLINE
Assunto principal:
Methylococcaceae
/
Coenzimas
/
Quinolonas
/
Precursores Enzimáticos
Idioma:
En
Revista:
Antonie Van Leeuwenhoek
Ano de publicação:
1989
Tipo de documento:
Article