Thirty-four of the 85 residues of the histidine-containing protein HPr of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system have been changed by site-directed mutagenesis. Many of the mutations have wild-type activity suggesting an unaltered tertiary structure but have altered binding to three monoclonal antibodies: Jel42, Jel44, and Jel323. This altered binding defines the residues that are involved in the epitopes of HPr. At present, two different three-dimensional structures have been determined for HPr, one from two-dimensional nuclear magnetic resonance spectra and the other from x-ray diffraction of HPr crystals. The epitope mapping for Jel42 does not distinguish between the tertiary structures. However, only the HPr structure derived from two-dimensional nuclear magnetic resonance spectra is consistent with a contiguous surface binding site that can be defined as the epitope for Jel44. Thus the x-ray structure may represent a partially unfolded HPr.
Submitter: Shu-Ching Ou
Submission Date: Feb. 27, 2019, 12:36 p.m.
Sequences for Jel44 and Jel323 are not found, thus the sequences/mutants associated with the binding data do not include sequences of these two monoclonal antibodies.
|Number of data points||332|
|Proteins||Phosphocarrier protein HPr|
|Assays/Quantities/Protocols||Experimental Assay: PTS (sugar phosphotransferase system) Activity ; Experimental Assay: Relative Binding Constant (Jel323) ; Experimental Assay: Relative Binding Constant (Jel44) ; Experimental Assay: Relative Binding Constant (Jel42) ; Derived Quantity: ΔΔG (Jel323) ; Derived Quantity: ΔΔG (Jel44) ; Derived Quantity: ΔΔG (Jel42)|
|Libraries||Binding associated with Jel42 ; Binding associated with Jel44 and Jel323; PTS activity|
|Percent Identity||Matching Chains||Protein||Accession||Entry Name|
|100.0||Phosphocarrier protein HPr||P0AA06||PTHP_ECO57|
|100.0||Phosphocarrier protein HPr||P0AA05||PTHP_ECOL6|
|100.0||Phosphocarrier protein HPr||P0AA04||PTHP_ECOLI|
|100.0||Phosphocarrier protein HPr||P0AA08||PTHP_SALTI|
|100.0||Phosphocarrier protein HPr||P0AA07||PTHP_SALTY|
|100.0||Phosphocarrier protein HPr||P0AA09||PTHP_SHIFL|
|98.8||Phosphocarrier protein HPr||P16481||PTHP_KLEPN|