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

• Published in: Scientific reports 2017-02, Vol.7 (1), p.43431-43431, Article 43431
• Main Authors: Choe, Mangyu, Park, Young-Ha, Lee, Chang-Ro, Kim, Yeon-Ran, Seok, Yeong-Jae
• Format: Article
• Language: English
• Subjects: 38/1; 38/77; 42; 45; 45/29; 631/326/1320; 631/326/325; 82; 82/1; 82/103; 82/16; 82/58; 82/80; 82/83; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological Transport; Carbon sources; E coli; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Fermentation; Gene Expression Regulation, Bacterial; Glucose; Glucose - metabolism; Glucose transport; Gram-negative bacteria; Humanities and Social Sciences; Kinases; Mannitol; Mannitol - metabolism; multidisciplinary; Operon; Phosphoenolpyruvate Sugar Phosphotransferase System - genetics; Phosphoenolpyruvate Sugar Phosphotransferase System - metabolism; Phosphorylation; Phosphotransferase; Repressor Proteins - genetics; Repressor Proteins - metabolism; Science; Sugar
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep43431

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