Sequential and spatially restricted interactions of assembly factors with an autotransporter β domain

摘要

Bacteria are classified as either Gram-positive or Gram-negative depending on the nature of their cell envelope. In contrast to Gram-positive bacteria, which are bounded by a single cell membrane, Gram-negative bacteria such as Escherichia coli are bounded by two cell membranes, an inner membrane (IM) and an outer membrane (OM). The composition of the OM is rather different from that of other biological membranes. Although the inner leaflet of the OM, like many other membranes, is composed of phospholi-pids, the outer leaflet is composed primarily of a glycolipid called "lipopolysaccharide," which forms a tightly packed structure that effectively blocks the entry of hydrophobic molecules (including many antibiotics) into the cell. Furthermore, most of the