(A) Schematic of the E. coli chemotaxis signaling pathway, highlighting component interactions connecting the periplasmic chemical environment to the direction of flagellar motor rotation as described in the main text. (B) Schematic of the E. coli chemosensory array, shown as the level of the array baseplate, illustrating the hexagonal arrangement of receptor trimers-of-dimers (TOD) interconnected by rings of CheA and CheW (pink circle) and CheW only (green circle). A single core signaling unit, along with two flanking CheW molecules, is isolated to the left. Chemoreceptors are shown in red and pink, CheA in shades of blue, and CheW in gold. Panel (B) was adapted from [52] with permission.