D-galactose catabolism in archaea: operation of the DeLey-Doudoroff pathway in Haloferax volcanii.
FEMS Microbiol Lett
; 367(1)2020 01 01.
Article
en En
| MEDLINE
| ID: mdl-32055827
The haloarchaeon Haloferax volcanii was found to grow on D-galactose as carbon and energy source. Here we report a comprehensive analysis of D-galactose catabolism in H. volcanii. Genome analyses indicated a cluster of genes encoding putative enzymes of the DeLey-Doudoroff pathway for D-galactose degradation including galactose dehydrogenase, galactonate dehydratase, 2-keto-3-deoxygalactonate kinase and 2-keto-3-deoxy-6-phosphogalactonate (KDPGal) aldolase. The recombinant galactose dehydrogenase and galactonate dehydratase showed high specificity for D-galactose and galactonate, respectively, whereas KDPGal aldolase was promiscuous in utilizing KDPGal and also the C4 epimer 2-keto-3-deoxy-6-phosphogluconate as substrates. Growth studies with knock-out mutants indicated the functional involvement of galactose dehydrogenase, galactonate dehydratase and KDPGal aldolase in D-galactose degradation. Further, the transcriptional regulator GacR was identified, which was characterized as an activator of genes of the DeLey-Doudoroff pathway. Finally, genes were identified encoding components of an ABC transporter and a knock-out mutant of the substrate binding protein indicated the functional involvement of this transporter in D-galactose uptake. This is the first report of D-galactose degradation via the DeLey-Doudoroff pathway in the domain of archaea.
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Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Haloferax volcanii
/
Genes Arqueales
/
Redes y Vías Metabólicas
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Galactosa
Idioma:
En
Revista:
FEMS Microbiol Lett
Año:
2020
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido