The Bacillus subtilis Gne (GneA, GalE) protein can catalyse UDP-glucose as well as UDP-N-acetylglucosamine 4-epimerisation.
Mutations in the Bacillus subtilis gene that affect the activity of the uridine diphosphate (UDP)-N-acetylglucosamine (GlcNAc) 4-epimerase (EC 5.1.3.7) were shown to map to galE, the structural gene of the UDP-glucose (Glc) 4-epimerase (EC 5.1.3.2). This genetic evidence that the same enzyme can catalyse the epimerisation of hexoses as well as of their N-acetylated forms is confirmed by in vitro assays with purified enzyme. It appears that in B. subtilis, Gne (GneA, GalE) is involved in two distinct and essential functions, i.e., cell detoxification under certain growth conditions and the biosynthesis of anionic cell wall polymers. We discuss the evidence that such enzymes capable of utilizing both UDP-hexoses and UDP-N-acetylhexosamines are present in other organisms.
Institut de Microbiologie Fondamentale, Bâtiment de Biologie, Université de Lausanne, CH-1015, Lausanne, Switzerland.
Blazenka
B
Soldo
Claudio
C
Scotti
Dimitri
D
Karamata
Vladimir
V
Lazarevic
D000117:Acetylglucosamine / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002384:Catalysis; D004926:Escherichia coli / Q000235:genetics; D006639:Histidine / Q000235:genetics; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D014534:UDPglucose 4-Epimerase / Q000235:genetics / Q000378:metabolism*; D014530:Uridine Diphosphate / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism*
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D006639:Histidine; D014530:Uridine Diphosphate; D014534:UDPglucose 4-Epimerase; C020551:galactose epimerase; D014532:Uridine Diphosphate Glucose; D000117:Acetylglucosamine