9srx
Cryo-EM structure of the Mlc repressor in complex with the glucose-specific IICB transporter
Structural highlights
FunctionPTGCB_ECOLI The phosphoenolpyruvate-dependent sugar phosphotransferase system (sugar PTS), a major carbohydrate active -transport system, catalyzes the phosphorylation of incoming sugar substrates concomitantly with their translocation across the cell membrane. This system is involved in glucose transport. This enzyme is also a chemoreceptor monitoring the environment for changes in sugar concentration. Publication Abstract from PubMedThe global transcriptional repressor Mlc of Escherichia coli regulates genes involved in carbohydrate transport and metabolism, particularly glucose uptake via the glucose-specific phosphotransferase system (PTS). Unlike conventional repressors, Mlc exemplifies a system in which interactions with diverse macromolecules govern its activity. Here, we present cryo-electron microscopy structures of Mlc alone and in complexes with regulatory partners, including the glucose-specific PTS transporter IICB(Glc), a cognate DNA operator and the anti-repressor MtfA, capturing multiple assemblies central to transcription control. These structures reveal the molecular architecture of Mlc and its interactions with binding partners. Together with molecular dynamics simulations, they provide insights into the structural dynamics of these complexes. Our findings establish the structural basis of membrane-transporter involvement in transcriptional regulation, the mechanism of anti-repressor action and DNA recognition. This work provides a structural framework for understanding bacterial transcriptional regulation across diverse systems. Structural basis of Mlc-mediated transcriptional regulation of carbohydrate metabolism.,Roth P, Fender I, Jeckelmann JM, Ucurum Z, Lemmin T, Fotiadis D Nat Commun. 2026 Jul 11. doi: 10.1038/s41467-026-75270-8. PMID:42436118[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
