Structural conservation of chemotaxis machinery across A rchaea and B acteria

Journal Article · Wed Apr 08 00:00:00 EDT 2015 · Environmental Microbiology Reports

DOI:https://doi.org/10.1111/1758-2229.12265· OSTI ID:1401606

Briegel, Ariane ^[1]; Ortega, Davi R. ^[1]; Huang, Audrey N. ^[1]; Oikonomou, Catherine M. ^[1]; Gunsalus, Robert P. ^[2]; Jensen, Grant J. ^[3]

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1. California Institute of Technology 1200 E. California Blvd. Pasadena CA 91125 USA
2. University of California Los Angeles 609 Charles E. Young Dr. S. Los Angeles CA USA
3. California Institute of Technology 1200 E. California Blvd. Pasadena CA 91125 USA, Howard Hughes Medical Institute 1200 E. California Blvd. Pasadena CA 91125 USA

Summary Chemotaxis allows cells to sense and respond to their environment. In B acteria, stimuli are detected by arrays of chemoreceptors that relay the signal to a two‐component regulatory system. These arrays take the form of highly stereotyped super‐lattices comprising hexagonally packed trimers‐of‐receptor‐dimers networked by rings of histidine kinase and coupling proteins. This structure is conserved across chemotactic B acteria, and between membrane‐bound and cytoplasmic arrays, and gives rise to the highly cooperative, dynamic nature of the signalling system. The chemotaxis system, absent in eukaryotes, is also found in A rchaea, where its structural details remain uncharacterized. Here we provide evidence that the chemotaxis machinery was not present in the last archaeal common ancestor, but rather was introduced in one of the waves of lateral gene transfer that occurred after the branching of Eukaryota but before the diversification of E uryarchaeota. Unlike in B acteria, the chemotaxis system then evolved largely vertically in A rchaea, with very few subsequent successful lateral gene transfer events. By electron cryotomography, we find that the structure of both membrane‐bound and cytoplasmic chemoreceptor arrays is conserved between B acteria and A rchaea, suggesting the fundamental importance of this signalling architecture across diverse prokaryotic lifestyles.

• Sponsoring Organization: USDOE
• OSTI ID: 1401606
• Journal Information: Environmental Microbiology Reports, Journal Name: Environmental Microbiology Reports Vol. 7 Journal Issue: 3; ISSN 1758-2229
• Publisher: Wiley-Blackwell
• Country of Publication: United States
• Language: English