4jbw

Crystal structure of E. coli maltose transporter MalFGK2 in complex with its regulatory protein EIIAglc

spinqualitylabelsall models 4jbw, resolution 3.91Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4jbw is a 12 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.913Å Ligands: PGV Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MALF_ECOLI Part of the binding-protein-dependent transport system for maltose; probably responsible for the translocation of the substrate across the membrane. Publication Abstract from PubMed Efficient carbon utilization is critical to the survival of microorganisms in competitive environments. To optimize energy usage, bacteria have developed an integrated control system to preferentially uptake carbohydrates that support rapid growth. The availability of a preferred carbon source, such as glucose, represses the synthesis and activities of proteins necessary for the transport and metabolism of secondary carbon sources. This regulatory phenomenon is defined as carbon catabolite repression. In enteric bacteria, the key player of carbon catabolite repression is a component of the glucose-specific phosphotransferase system, enzyme IIA (EIIAGlc). It is known that unphosphorylated EIIAGlc binds to and inhibits a variety of transporters when glucose is available. However, understanding the underlying molecular mechanism has been hindered by the complete absence of structures for any EIIAGlc-transporter complexes. Here we present the 3.9 A crystal structure of Escherichia coli EIIAGlc in complex with the maltose transporter, an ATP-binding cassette (ABC) transporter. The structure shows that two EIIAGlc molecules bind to the cytoplasmic ATPase subunits, stabilizing the transporter in an inward-facing conformation and preventing the structural rearrangements necessary for ATP hydrolysis. We also show that the half-maximal inhibitory concentrations of the full-length EIIAGlc and an amino-terminal truncation mutant differ by 60-fold, consistent with the hypothesis that the amino-terminal region, disordered in the crystal structure, functions as a membrane anchor to increase the effective EIIAGlc concentration at the membrane. Together these data suggest a model of how the central regulatory protein EIIAGlc allosterically inhibits maltose uptake in E. coli. Carbon catabolite repression of the maltose transporter revealed by X-ray crystallography.,Chen S, Oldham ML, Davidson AL, Chen J Nature. 2013 Jun 16. doi: 10.1038/nature12232. PMID:23770568 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Maltose-binding protein 3D structures Phosphotransferase 3D structures

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