Atypical chemoreceptor arrays accommodate high membrane curvature

• Published in: Nature communications Vol. 11; no. 1; pp. 5763 - 13
• Main Authors: Muok, Alise R., Ortega, Davi R., Kurniyati, Kurni, Yang, Wen, Maschmann, Zachary A., Sidi Mabrouk, Adam, Li, Chunhao, Crane, Brian R., Briegel, Ariane
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.11.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 101/28; 45; 631/326; 631/326/41; 631/45/535/1258/1260; 82/58; 82/83; Amino Acid Sequence; Arrays; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; BASIC BIOLOGICAL SCIENCES; Cell Membrane - metabolism; Cell Membrane - ultrastructure; CheA protein; Chemoreception; Chemoreceptor Cells - cytology; Chemoreceptor Cells - metabolism; Chemoreceptors; Chemotaxis; Conserved Sequence; Cryoelectron tomography; Curvature; Dimerization; Escherichia coli - cytology; Fusion protein; Gene Deletion; Histidine; Histidine kinase; Histidine Kinase - metabolism; Humanities and Social Sciences; Kinases; Membranes; Microbiology; multidisciplinary; Oxygen probes; Protein Domains; Proteins; Science; Science (multidisciplinary); Sequence Homology, Amino Acid; Signal transduction; Signalling systems; Symmetry; Treponema - metabolism; Treponema denticola
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-19628-6

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. The main components of the prokaryotic chemotaxis system, chemoreceptors, organize into a hexagonal (P6 symmetry) extended array. Here authors use cryo-ET and 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.