Metabolism of Gentiobiose in Aerobacter aerogenes

AUTOR(ES)
RESUMO

Cleavage of gentiobiose in cell extracts of gentiobiose-grown Aerobacter aerogenes was dependent on the presence of adenosine 5′-triphosphate (ATP). The enzymes that participate in the overall reaction were shown to be a β-glucoside kinase, which catalyzes the phosphorylation of gentiobiose with ATP to form gentiobiose monophosphate [6-O-phosphoryl-β-d-glucopyranosyl-(1 → 6)-d-glucose], and a phospho-β-glucosidase, which catalyzes the hydrolytic cleavage of gentiobiose monophosphate to form equimolar amounts of d-glucose and d-glucose 6-phosphate. Although the β-glucoside kinase was previously shown to catalyze the phosphorylation of many β-glucosides that serve as growth substrates (i.e., gentiobiose, cellobiose, cellobiitol, salicin, arbutin, methyl β-d-glucoside, and phenyl β-d-glucoside), mutant analysis and induction studies indicate that it functions only in the metabolism of gentiobiose, cellobiose, and cellobiitol.

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