Universal architecture of bacterial chemoreceptor arrays.
Chemoreceptors are key components of the high-performance signal transduction system that controls bacterial chemotaxis. Chemoreceptors are typically localized in a cluster at the cell pole, where interactions among the receptors in the cluster are thought to contribute to the high sensitivity, wide dynamic range, and precise adaptation of the signaling system. Previous structural and genomic studies have produced conflicting models, however, for the arrangement of the chemoreceptors in the clusters. Using whole-cell electron cryo-tomography, here we show that chemoreceptors of different classes and in many different species representing several major bacterial phyla are all arranged into a highly conserved, 12-nm hexagonal array consistent with the proposed "trimer of dimers" organization. The various observed lengths of the receptors confirm current models for the methylation, flexible bundle, signaling, and linker sub-domains in vivo. Our results suggest that the basic mechanism and function of receptor clustering is universal among bacterial species and was thus conserved during evolution.
Briegel
Ariane
A
Divisions of Biology and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA.
Ortega
Davi R
DR
Tocheva
Elitza I
EI
Wuichet
Kristin
K
Li
Zhuo
Z
Chen
Songye
S
Müller
Axel
A
Iancu
Cristina V
CV
Murphy
Gavin E
GE
Dobro
Megan J
MJ
Zhulin
Igor B
IB
Jensen
Grant J
GJ
D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics*; D016935:Caulobacter crescentus / Q000235:genetics / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D030541:Databases, Genetic; D055032:Electron Microscope Tomography; D004926:Escherichia coli / Q000235:genetics / Q000648:ultrastructure; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D008565:Membrane Proteins / Q000145:classification / Q000235:genetics*; D000072236:Methyl-Accepting Chemotaxis Proteins; D010802:Phylogeny; D020124:Thermotoga maritima / Q000235:genetics / Q000648:ultrastructure
D001426:Bacterial Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins