Chemoreceptors in Caulobacter crescentus: trimers of receptor dimers in a partially ordered hexagonally packed array.
Chemoreceptor arrays are macromolecular complexes that form extended assemblies primarily at the poles of bacterial cells and mediate chemotaxis signal transduction, ultimately controlling cellular motility. We have used cryo-electron tomography to determine the spatial distribution and molecular architecture of signaling molecules that comprise chemoreceptor arrays in wild-type Caulobacter crescentus cells. We demonstrate that chemoreceptors are organized as trimers of receptor dimers, forming partially ordered hexagonally packed arrays of signaling complexes in the cytoplasmic membrane. This novel organization at the threshold between order and disorder suggests how chemoreceptors and associated molecules are arranged in signaling assemblies to respond dynamically in the activation and adaptation steps of bacterial chemotaxis.
Khursigara
Cezar M
CM
Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Wu
Xiongwu
X
Subramaniam
Sriram
S
D001426:Bacterial Proteins; D016935:Caulobacter crescentus / Q000737:chemistry* / Q000648:ultrastructure; D002628:Chemoreceptor Cells / Q000737:chemistry* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D046911:Macromolecular Substances; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D011956:Receptors, Cell Surface
D001426:Bacterial Proteins; D046911:Macromolecular Substances; D011956:Receptors, Cell Surface