MICROBIOLOGY AND MOLECULAR BIOLOGY REVIEWS, Mar. 2007, p. 158–229 Vol. 71, No. 1 1092-2172/07/$08.00ϩ0 doi:10.1128/MMBR.00036-06 Copyright © 2007, American Society for Microbiology. All Rights Reserved. Colicin Biology† Eric Cascales,1* Susan K. Buchanan,2 Denis Duche´,1 Colin Kleanthous,3 Roland Lloube`s,1 Kathleen Postle,4 Margaret Riley,5 Stephen Slatin,6 and Danie`le Cavard1 Laboratoire d’Inge´nierie des Syste`mes Macromole´culaires, Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique, UPR9027, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France1; Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 208922; Department of Biology Area 10, P.O. Box 373, University of York, York YO10 5YW, United Kingdom3; 301 Althouse Laboratory, Department of Biochemistry and Molecular Biology, Eberly College of Science, Pennsylvania State University, University Park, Pennsylvania 168024; Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts 010035; and Department of Physiology and Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 104616 INTRODUCTION .......................................................................................................................................................160 Downloaded from COLICIN SYNTHESIS..............................................................................................................................................162 Colicinogenic Plasmids ..........................................................................................................................................162 Colicin Operons: Gene Organization and Regulation.......................................................................................162 Colicin Expression ..................................................................................................................................................164 Lethality of Colicin Production.............................................................................................................................164 COLICIN RELEASE ..................................................................................................................................................164 mmbr.asm.org Sequence, Synthesis, and Localization of the Colicin Lysis Proteins .............................................................165 Functions of Colicin Lysis Proteins .....................................................................................................................166 Colicin release .....................................................................................................................................................166 Quasilysis.............................................................................................................................................................166 Modifications of cell envelope structure..........................................................................................................166 at Univ of Massachusetts Amherst on June 21, 2010 Activation of OmpLA, the outer membrane phospholipase A......................................................................167 Death of the host cell .........................................................................................................................................167 Regulator of expression of the colicin operon ................................................................................................167 Structure-Function Relationships of Colicin Lysis Proteins ............................................................................167 Mechanism of Action of Colicin Lysis Proteins .................................................................................................168 STRUCTURAL ORGANIZATION OF COLICINS ...............................................................................................169 Domain Organization of Colicins.........................................................................................................................170 Specific Functions of Colicin Domains................................................................................................................170 Three-Dimensional Structures of Colicins ..........................................................................................................173 COLICIN RECEPTION.............................................................................................................................................174 Recognition of the Receptor at the Bacterial Cell Surface...............................................................................174 Binding to the Receptor.........................................................................................................................................174 Competition with the Natural Ligand..................................................................................................................176 Colicin Cleavage at the Cell Surface ...................................................................................................................176 Energy Requirements for Receptor Binding .......................................................................................................177 Release of Immunity...............................................................................................................................................177 Reception of Bacteriophages .................................................................................................................................177 COLICIN IMPORT....................................................................................................................................................178 TRANSLOCATION THROUGH THE OUTER MEMBRANE ............................................................................178 Tol-Dependent Colicins..........................................................................................................................................178 TonB-Dependent Colicins ......................................................................................................................................178 TRANSIT THROUGH THE PERIPLASM .............................................................................................................179 General Principles of Colicin Transit..................................................................................................................179 Tol-Dependent Colicins..........................................................................................................................................179 The Tol system ....................................................................................................................................................179 (i) Identification..............................................................................................................................................179 (ii) Regulation .................................................................................................................................................179 (iii) Localization and topology......................................................................................................................179 (iv) Three-dimensional structures................................................................................................................180 (v) Interaction network ..................................................................................................................................180 * Corresponding author. Mailing address: Laboratoire d’Inge´nierie des Syste`mes Macromole´culaires, IBSM, CNRS UPR9027, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. Phone: (33) 491 164 663. Fax: (33) 491 712 124. E-mail: [email protected]. † This review is dedicated to Robert Kadner (1942–2005). 158 VOL. 71, 2007 COLICIN BIOLOGY 159 (vi) Physiological functions ...........................................................................................................................181 Interactions between Tol subunits and colicin translocation domains.......................................................182 (i) Interaction with the TolA protein...........................................................................................................182 (ii) Interaction with the TolB protein..........................................................................................................183 (iii) Interaction with the TolR and TolQ proteins.....................................................................................183 Definition of Tol boxes.......................................................................................................................................184 (i) TolA binding sequence..............................................................................................................................184 (ii) TolB binding sequence ............................................................................................................................184 (iii) TolR binding sequence...........................................................................................................................184 Structural information on Tol-dependent translocation...............................................................................184