Identification and characterization of oxalate oxidoreductase, a novel thiamine pyrophosphate-dependent 2-oxoacid oxidoreductase that enables anaerobic growth on oxalate.
J Biol Chem
; 285(52): 40515-24, 2010 Dec 24.
Article
em En
| MEDLINE
| ID: mdl-20956531
ABSTRACT
Moorella thermoacetica is an anaerobic acetogen, a class of bacteria that is found in the soil, the animal gastrointestinal tract, and the rumen. This organism engages the Wood-Ljungdahl pathway of anaerobic CO(2) fixation for heterotrophic or autotrophic growth. This paper describes a novel enzyme, oxalate oxidoreductase (OOR), that enables M. thermoacetica to grow on oxalate, which is produced in soil and is a common component of kidney stones. Exposure to oxalate leads to the induction of three proteins that are subunits of OOR, which oxidizes oxalate coupled to the production of two electrons and CO(2) or bicarbonate. Like other members of the 2-oxoacidferredoxin oxidoreductase family, OOR contains thiamine pyrophosphate and three [Fe(4)S(4)] clusters. However, unlike previously characterized members of this family, OOR does not use coenzyme A as a substrate. Oxalate is oxidized with a k(cat) of 0.09 s(-1) and a K(m) of 58 µM at pH 8. OOR also oxidizes a few other 2-oxoacids (which do not induce OOR) also without any requirement for CoA. The enzyme transfers its reducing equivalents to a broad range of electron acceptors, including ferredoxin and the nickel-dependent carbon monoxide dehydrogenase. In conjunction with the well characterized Wood-Ljungdahl pathway, OOR should be sufficient for oxalate metabolism by M. thermoacetica, and it constitutes a novel pathway for oxalate metabolism.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxalatos
/
Oxirredutases
/
Tiamina Pirofosfatase
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Proteínas de Bactérias
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Dióxido de Carbono
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Moorella
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos