1O2F

COMPLEX OF ENZYME IIAGLC AND IIBGLC PHOSPHOCARRIER PROTEIN HPR FROM ESCHERICHIA COLI NMR, RESTRAINED REGULARIZED MEAN STRUCTURE

Summary for 1O2F

• Entry DOI: 10.2210/pdb1o2f/pdb
• Descriptor: PTS system, glucose-specific IIA component, PTS system, glucose-specific IIBC component, PHOSPHITE ION (3 entities in total)
• Functional Keywords: phosphotransferase, transferase, kinase, sugar transport, complex (transferase-phosphocarrier)
• Biological source: Escherichia coli; More
• Cellular location: Cytoplasm: P69783; Cell inner membrane; Multi-pass membrane protein: P69786
• Total number of polymer chains: 2
• Total formula weight: 27477.19

Authors

Clore, G.M.,Cai, M.,Williams, D.C. (deposition date: 2003-03-11, release date: 2003-05-13, Last modification date: 2023-12-27)

Primary citation

Cai, M.,Williams Jr., D.C.,Wang, G.,Lee, B.R.,Peterkofsky, A.,Clore, G.M.
Solution Structure of the Phosphoryl Transfer Complex between the Signal-transducing Protein IIAGlucose and the Cytoplasmic Domain of the Glucose Transporter IICBGlucose of the Escherichia coli Glucose Phosphotransferase System.
J.Biol.Chem., 278:25191-25206, 2003

PubMed Abstract: The solution structure of the final phosphoryl transfer complex in the glucose-specific arm of the Escherichia coli phosphotransferase system, between enzyme IIAGlucose (IIAGlc) and the cytoplasmic B domain (IIBGlc) of the glucose transporter IICBGlc, has been solved by NMR. The interface (approximately 1200-A2 buried surface) is formed by the interaction of a concave depression on IIAGlc with a convex protrusion on IIBGlc. The phosphoryl donor and acceptor residues, His-90 of IIAGlc and Cys-35 of IIBGlc (residues of IIBGlc are denoted in italics) are in close proximity and buried at the center of the interface. Cys-35 is primed for nucleophilic attack on the phosphorus atom by stabilization of the thiolate anion (pKa approximately 6.5) through intramolecular hydrogen bonding interactions with several adjacent backbone amide groups. Hydrophobic intermolecular contacts are supplemented by peripheral electrostatic interactions involving an alternating distribution of positively and negatively charged residues on the interaction surfaces of both proteins. Salt bridges between the Asp-38/Asp-94 pair of IIAGlc and the Arg-38/Arg-40 pair of IIBGlc neutralize the accumulation of negative charge in the vicinity of both the Sgamma atom of Cys-35 and the phosphoryl group in the complex. A pentacoordinate phosphoryl transition state is readily accommodated without any change in backbone conformation, and the structure of the complex accounts for the preferred directionality of phosphoryl transfer between IIAGlc and IIBGlc. The structures of IIAGlc.IIBGlc and the two upstream complexes of the glucose phosphotransferase system (EI.HPr and IIAGlc.HPr) reveal a cascade in which highly overlapping binding sites on HPr and IIAGlc recognize structurally diverse proteins.

PubMed: 12716891
DOI: 10.1074/jbc.M302677200

Experimental method

SOLUTION NMR