Open AccessThe Caulobacter Tol-Pal Complex Is Essential for Outer Membrane Integrity and the Positioning of a Polar Localization Factor
Author(s) -
Yi Chun Yeh,
Luis R. Comolli,
Kenneth H. Downing,
Lucy Shapiro,
Harley H. McAdams
Publication year - 2010
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.00607-10
Subject(s) - caulobacter crescentus , biology , cell division , microbiology and biotechnology , histidine kinase , bacterial outer membrane , transmembrane protein , cell envelope , cell membrane , cytokinesis , inner membrane , cell polarity , mutant , cell cycle , cell , biochemistry , escherichia coli , receptor , gene , mitochondrion
Cell division inCaulobacter crescentus involves constriction and fission of the inner membrane (IM) followed about 20 min later by fission of the outer membrane (OM) and daughter cell separation. In contrast toEscherichia coli , theCaulobacter Tol-Pal complex is essential. Cryo-electron microscopy images of theCaulobacter cell envelope exhibited outer membrane disruption, and cells failed to complete cell division in TolA, TolB, or Pal mutant strains. In wild-type cells, components of the Tol-Pal complex localize to the division plane in early predivisional cells and remain predominantly at the new pole of swarmer and stalked progeny upon completion of division. The Tol-Pal complex is required to maintain the position of the transmembrane TipN polar marker, and indirectly the PleC histidine kinase, at the cell pole, but it is not required for the polar maintenance of other transmembrane and membrane-associated polar proteins tested. Coimmunoprecipitation experiments show that both TolA and Pal interact directly or indirectly with TipN. We propose that disruption of thetrans -envelope Tol-Pal complex releases TipN from its subcellular position. TheCaulobacter Tol-Pal complex is thus a key component of cell envelope structure and function, mediating OM constriction at the final step of cell division as well as the positioning of a protein localization factor.