Abstract

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.

Submission Details

ID: xawcnBDF

Submitter: Shu-Ching Ou

Submission Date: Feb. 27, 2019, 12:36 p.m.

Version: 1

Publication Details

Sharma S;Georges F;Delbaere LT;Lee JS;Klevit RE;Waygood EB,Proc Natl Acad Sci U S A (1991) Epitope mapping by mutagenesis distinguishes between the two tertiary structures of the histidine-containing protein HPr. PMID:1711212

Additional Information

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.