The general PTS component HPr determines the preference for glucose over mannitol

• DOI: 10.1038/srep43431
• Publication Date: 2017-02-22T11:43:14Z
• Authors: Mangyu Choe; Young-Ha Park; Chang-Ro Lee; Yeon-Ran Kim; Yeong-Jae Seok
• Keywords: PEP group translocation; Carbohydrate Metabolism; Phosphotransferases

Preferential sugar utilization is a widespread phenomenon in biological systems. Glucose usually the most preferred carbon source various organisms, especially bacteria where it taken up via phosphoenolpyruvate:sugar phosphotransferase system (PTS). The currently proposed model for glucose preference over non-PTS sugars enteric including E. coli strictly dependent on phosphorylation state of glucose-specific PTS component, enzyme IIAGlc (EIIAGlc). However, mechanism among largely unknown Gram-negative bacteria. Here, we show that another sugar, mannitol, absolutely general component HPr, but not EIIAGlc, coli. Dephosphorylated HPr accumulates during transport and interacts with mannitol operon regulator, MtlR, to augment its repressor activity. This interaction blocks inductive effect expression results inhibition utilization.