[Advances in mechanism of Escherichia coli carbon catabolite repression].
Bacteria often sequentially utilize coexisting carbohydrates in environment and firstly select the one (frequently glucose) easiest to metabolize. This phenomenon is known as carbon catabolite repression (CCR). In existing Chinese teaching materials of molecular biology and related courses, unclear or even wrong interpretations are given about CCR mechanism. A large number of studies have shown that rather than the existence of intracellular glucose, CCR is mainly caused by the glucose transport process coupling with glucose phosphorylation via the phosphoenolpyruvate: carbohydrate phosphotransferase system PTS. The transport process leads to accumulation of dephosphorylated form of EAGlc.This form of EAGlc can bind the membrane-localized LacY protein to block the uptake of lactose inducer. cAMP functions in activation of key genes involved in PTS system to strengthen the role of inducer exclusion. In addition, dephosphorylated form of EBGlc and Yee bind global transcription repressor Mlc to ensure the expression of key genes involved in the PTS system. This review summarizes the current advancement in mechanism of Escherichia coli carbon catabolite repression.
Ma
Wan-Qing
WQ
Tianjin Key Laboratory of Cyto-Genetical and Molecular Regulation, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China.
Zhang
Zhen
Z
Liu
Yue-Lin
YL
Wang
Hua-Zhong
HZ
D050260:Carbohydrate Metabolism; D000242:Cyclic AMP / Q000502:physiology; D002373:Cyclic AMP Receptor Protein / Q000502:physiology; D004926:Escherichia coli / Q000378:metabolism*; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000502:physiology
D002373:Cyclic AMP Receptor Protein; D000242:Cyclic AMP; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System