Churchward Gordon
Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Mol Microbiol. 2008 Nov;70(3):554-6. doi: 10.1111/j.1365-2958.2008.06415.x. Epub 2008 Aug 25.
The analysis of bacterial genomes has revealed an extraordinary array of conjugal elements (integrative and conjugative element or ICE) that reside in bacterial chromosomes. These elements contribute to the pan-genomes of individual species and confer a wide variety of properties on their bacterial hosts. ICEBs1 is a conjugal element found in Bacillus subtilis that has a remarkable regulatory mechanism that apparently favours conjugation when there are suitable recipient bacteria at high density or when the bacterial host is facing DNA-damaging stresses. In the current issue, Bose et al. dissect the mechanism of induction of transfer of this element, and reveal a new, apparently widespread repressor anti-repressor system and a new mechanism of repressor destruction by proteolysis.
细菌基因组分析揭示了一系列存在于细菌染色体中的非凡接合元件（整合性接合元件或ICE）。这些元件构成了各个物种的泛基因组，并赋予其细菌宿主各种各样的特性。ICEBs1是在枯草芽孢杆菌中发现的一种接合元件，它具有一种非凡的调控机制，当存在高密度的合适受体细菌时，或者当细菌宿主面临DNA损伤应激时，这种机制显然有利于接合作用。在本期中，博斯等人剖析了该元件转移诱导机制，揭示了一种新的、显然广泛存在的阻遏物-抗阻遏物系统以及一种通过蛋白水解破坏阻遏物的新机制。
