Molecular Microbiology, the leading primary journal in the microbial sciences, publishes molecular studies of Bacteria, Archaea, eukaryotic microorganisms, and their viruses.Research papers should lead to a deeper understanding of the molecular principles underlying basic physiological processes or mechanisms. Appropriate topics include gene expression and regulation, pathogenicity and virulence, physiology and metabolism, synthesis of macromolecules (proteins, nucleic acids, lipids, polysaccharides, etc), cell biology and subcellular organization, membrane biogenesis and function, traffic and transport, cell-cell communication and signalling pathways, evolution and gene transfer. Articles focused on host responses (cellular or immunological) to pathogens or on microbial ecology should be directed to our sister journals Cellular Microbiology and Environmental Microbiology, respectively.