Polar Positioning of a Conjugation Protein from the Integrative and Conjugative Element ICEBs1ofBacillus subtilis

Abstract

ICEBs1 is an integrative and conjugative element found in the chromosome of Bacillus subtilis. ICEBs1 encodes functions needed for its excision and transfer to recipient cells. We found that the ICEBs1 gene conE (formerly yddE) is required for conjugation and that conjugative transfer of ICEBs1 requires a conserved ATPase motif of ConE. ConE belongs to the HerA/FtsK superfamily of ATPases, which includes the wellcharacterized proteins FtsK, SpoIIIE, VirB4, and VirD4. We found that a ConE-GFP (green fluorescent protein) fusion associated with the membrane predominantly at the cell poles in ICEBs1 donor cells. At least one ICEBs1 product likely interacts with ConE to target it to the membrane and cell poles, as ConE-GFP was dispersed throughout the cytoplasm in a strain lacking ICEBs1. We also visualized the subcellular location of

Biology of Three ICE Families: SXT/R391, ICE Bs1 , and ICE St1 /ICE St3

“…Most of the predicted or experimentally demonstrated transfer proteins encoded by ICEBs1 have homologs encoded by conjugative plasmids found in the Firmicutes. Four of these proteins are homologous to VirB1, VirB4, VirB11, and VirD4 proteins, which belong to inner membrane part of the T4SS of conjugative plasmids found in Gram-negative bacteria (72,73,74). Interestingly, the genes encoding the site-specific recombination functions and allowing intracellular mobility of ICEBs1 are not grouped in the same region.…”

“…Several observations suggested that ICEBs1 was capable of extrachromosomal replication, such as the relative stability of a ΔimmR mutant and the relocalization of the replisome during ICEBs1 conjugative transfer (72,78). Further studies led to a precise model of RC replication of the activated extrachromosomal circular form of ICEBs1 (98).…”

“…B. subtilis grows in chains of several connected cells in which ICEBs1 can rapidly spread by conjugation, thereby invading the whole chain from a single transconjugant (81). The VirB4-like protein ConE, an ATPase of the HerA/FtsK superfamily, is required for the transfer of ICEBs1 (72,82). Specific localization of ConE at the cell poles might be a key factor in the intrachain transfer of ICEBs1.…”

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae

“…In strain 2603V/R, IS1381 interrupts a gene (sag2004/sag2001) predicted to encode a conjugal transfer protein belonging to the ConE/YddE family (Tettelin et al, 2002). In Bacillus subtilis, ConE is an ATPase of the FtsK/HerA superfamily that is required for the conjugative transfer of ICEBs1 (Berkmen et al, 2010). This suggests that IS1381 might be involved in the regulation of horizontal gene transfer.…”

Highly variable individual donor cell fates characterize robust horizontal gene transfer of an integrative and conjugative element

“…1A). In the receiving cell, the ICE must ensure effective integration to avoid being lost upon cell division because of its limited selfreplication capacity (22,23) (Fig. 1B).…”