Cross-talk between the L-sorbose and D-sorbitol (D-glucitol) metabolic pathways in Lactobacillus casei.
A gene encoding sorbitol-6-phosphate dehydrogenase (SorF) belonging to the sorbose operon (sorFABCDG) has been characterized in Lactobacillus casei. Inactivation of this gene revealed the presence of another sorbitol-6-phosphate dehydrogenase that was induced by D-sorbitol (D-glucitol). The gene encoding this activity (gutF) has also been isolated, sequenced and disrupted. The sorbitol-6-phosphate dehydrogenase genes (sorF, gutF) were required for growth on L-sorbose and D-sorbitol, respectively. Biochemical and transcriptional analyses of the wild-type and mutant strains demonstrated that L-sorbose and D-sorbitol induced sorF and the gene encoding the sorbose operon activator (sorR), while the expression of gutF was only activated by D-sorbitol. Furthermore, these studies indirectly suggested that a common metabolite of the L-sorbose and D-sorbitol metabolic pathways (probably D-sorbitol 6-phosphate) would act as the effector of SorR. The same effector would also be the inducer of gutF, although the two pathways seem to be subject to distinct regulatory mechanisms.
Yebra
Marı A J
MAJ
Departamento de Biotecnologı́a, Instituto de Agroquı́mica y Tecnologı́a de Alimentos, CSIC, Apdo. Correos 73, 46100 Burjassot, Spain1.
Pérez-Martı Nez
Gaspar
G
Departamento de Biotecnologı́a, Instituto de Agroquı́mica y Tecnologı́a de Alimentos, CSIC, Apdo. Correos 73, 46100 Burjassot, Spain1.
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D015964:Gene Expression Regulation, Bacterial; D007780:Lacticaseibacillus casei / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D013012:Sorbitol / Q000378:metabolism*; D013013:Sorbose / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D013012:Sorbitol; D013013:Sorbose