Structure and function of the Escherichia coli Tol-Pal stator protein TolR

Abstract

Background: TolR forms part of the proton-motive force (pmf)-linked stator of the Tol-Pal complex in bacteria. Results: Structural and biophysical analysis shows the periplasmic domain of TolR to be a strand-swapped dimer. Conclusion: Strand swapping blocks peptidoglycan binding by TolR. Significance: Pmf-linked stator proteins must disassemble strand-swapped dimer structures to traverse the periplasm and bind peptidoglycan.