How bacteria protect themselves against channel-forming colicins Authors Guillermina Alonso Experimental Biology Institute, Faculty of Science, Venezuelan Central University, Caracas, Venezuela Glenda Vílchez Experimental Biology Institute, Faculty of Science, Venezuelan Central University, Caracas, Venezuela Vidal Rodríguez Lemoine Experimental Biology Institute, Faculty of Science, Venezuelan Central University, Caracas, Venezuela Keywords: channel-forming colicins, H plasmids, PacB character, tellurite, translocation systems Abstract Here we review the mechanisms that bacterial cells use to protect themselves against channel-forming colicins. Four mechanisms are examined: immunity, resistance, tolerance and PacB character. Immunity confers protection to colicinogenic cells against the colicin they produce, since the colicinogenic plasmid bears the genetic determinant for such immunity protein. Resistance is provided by modifications on colicin receptors located on the outer membrane. It prevents colicin adsorption and protects against those colicins sharing a common receptor. Tolerance is achieved by changes in the translocation system. The adsorbed colicin is not translocated toward the periplasmic space. This impedes its insertion into the cell membrane as well as the formation of the transmembrane channel. Tolerance confers protection against colicins that share the same translocation system. Finally, we discuss the PacB character, that confers protection against all known channel-forming colicins. The latter property is encoded by non-colicinogenic plasmids in the Hincompatibility complex. Downloads PDF Published 2010-03-15 Issue Vol. 3 No. 2 (2000) Section Review Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
