6KCR

X-ray structure of the MtlR-HPr complex from Escherichia coli

Summary for 6KCR

• Entry DOI: 10.2210/pdb6kcr/pdb
• Descriptor: Mannitol operon repressor, Phosphocarrier protein HPr (2 entities in total)
• Functional Keywords: mtlr, hpr, glucose repression of mannitol operon, phosphotransferase system, gene regulation
• Biological source: Escherichia coli K-12; More
• Total number of polymer chains: 4
• Total formula weight: 63938.61

Authors

Choe, M.,Woo, J.S.,Seok, Y.J. (deposition date: 2019-06-28, release date: 2019-10-09, Last modification date: 2023-11-22)

Primary citation

Choe, M.,Min, H.,Park, Y.H.,Kim, Y.R.,Woo, J.S.,Seok, Y.J.
Structural insight into glucose repression of the mannitol operon.
Sci Rep, 9:13930-13930, 2019

PubMed Abstract: Carbon catabolite repression is a regulatory mechanism to ensure sequential utilization of carbohydrates and is usually accomplished by repression of genes for the transport and metabolism of less preferred carbon compounds by a more preferred one. Although glucose and mannitol share the general components, enzyme I and HPr, of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) for their transport, glucose represses the transport and metabolism of mannitol in a manner dependent on the mannitol operon repressor MtlR in Escherichia coli. In a recent study, we identified the dephosphorylated form of HPr as a regulator determining the glucose preference over mannitol by interacting with and augmenting the repressor activity of MtlR in E. coli. Here, we determined the X-ray structure of the MtlR-HPr complex at 3.5 Å resolution to understand how phosphorylation of HPr impedes its interaction with MtlR. The phosphorylation site (His15) of HPr is located close to Glu108 and Glu140 of MtlR and phosphorylation at His15 causes electrostatic repulsion between the two proteins. Based on this structural insight and comparative sequence analyses, we suggest that the determination of the glucose preference over mannitol solely by the MtlR-HPr interaction is conserved within  the Enterobacteriaceae family.

PubMed: 31558743
DOI: 10.1038/s41598-019-50249-2

Experimental method

X-RAY DIFFRACTION (3.5 Å)