title: Colicin A binds to a novel binding site of TolA in the Escherichia coli periplasm.
abstract: Colicins are protein antibiotics produced by Escherichia coli to kill closely related non-identical competing species. They have taken advantage of the promiscuity of several proteins in the cell envelope for entry into the bacterial cell. The Tol-Pal system comprises one such ensemble of periplasmic and membrane-associated interacting proteins that links the IM (inner membrane) and OM (outer membrane) and provides the cell with a structural scaffold for cell division and energy transduction. Central to the Tol-Pal system is the TolA hub protein which forms protein-protein interactions with all other members and also with extrinsic proteins such as colicins A, E1, E2-E9 and N, and the coat proteins of the Ff family of filamentous bacteriophages. In the present paper, we review the role of TolA in the translocation of colicin A through the recently determined crystal structure of the complex of TolA with a translocation domain peptide of ColA (TA53-107), we demonstrate that TA53-107 binds to TolA at a novel binding site and compare the interactions of TolA with other colicins that use the Tol-Pal system for cell entry substantiating further the role of TolA as a periplasmic hub protein.
authors.affiliation: School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK. chris.penfold@nottingham.ac.uk
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Penfold
authors.forename: Chan
authors.initials: C
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Mireille
authors.initials: M
authors.lastname: Vankemmelbeke
authors.forename: Richard
authors.initials: R
authors.lastname: James
mesh_terms: D001665:Binding Sites; D003087:Colicins / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000502:physiology*; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry; D019897:Periplasm / Q000378:metabolism*; D033903:Periplasmic Proteins / Q000737:chemistry / Q000502:physiology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport
chemical_list: D003087:Colicins; D029968:Escherichia coli Proteins; D010446:Peptide Fragments; D033903:Periplasmic Proteins; C062093:tolA protein, E coli