Atypical chemoreceptor arrays accommodate high membrane curvature.

Publication Type:

Journal Article


Nat Commun, Volume 11, Issue 1, p.5763 (2020)


Amino Acid Sequence, Bacterial Proteins, Cell Membrane, Chemoreceptor Cells, Chemotaxis, Conserved Sequence, Escherichia coli, Gene Deletion, Histidine Kinase, Protein Domains, Sequence Homology, Amino Acid, Treponema


<p>The prokaryotic chemotaxis system is arguably the best-understood signaling pathway in biology. In all previously described species, chemoreceptors organize into a hexagonal (P6 symmetry) extended array. Here, we report an alternative symmetry (P2) of the chemotaxis apparatus that emerges from a strict linear organization of the histidine kinase CheA in Treponema denticola cells, which possesses arrays with the highest native curvature investigated thus far. Using cryo-ET, we reveal that Td chemoreceptor arrays assume an unusual arrangement of the supra-molecular protein assembly that has likely evolved to accommodate the high membrane curvature. The arrays have several atypical features, such as an extended dimerization domain of CheA and a variant CheW-CheR-like fusion protein that is critical for maintaining an ordered chemosensory apparatus. Furthermore, the previously characterized Td oxygen sensor ODP influences CheA ordering. These results suggest a greater diversity of the chemotaxis signaling system than previously thought.</p>