Chromosome-Membrane Interactions in Bacteria

Prokaryotes, by definition, do not segregate their genetic material from the cytoplasm. Thus, there is no barrier preventing direct interactions between chromosomal DNA and the plasma membrane. The possibility of such interactions in bacteria was proposed long ago and supported by early electron microscopy and cell fractionation studies. However, the identification and characterization of chromosome-membrane interactions have been slow in coming. Recently, this subject has seen more progress, driven by advances in imaging techniques and in the exploration of diverse cellular processes. A number of loci have been identified in specific bacteria that depend on interactions with the membrane for their function. In addition, there is growing support for a general mechanism of DNA-membrane contacts based on transertion-concurrent transcription, translation, and insertion of membrane proteins. This review summarizes the history and recent results of chromosome-membrane associations and discusses the known and theorized consequences of these interactions in the bacterial cell.