PT  - JOURNAL ARTICLE
AU  - Ariane Briegel
AU  - Catherine M. Oikonomou
AU  - Yi-Wei Chang
AU  - Andreas Kjaer
AU  - Audrey N. Huang
AU  - Ki Woo Kim
AU  - Debnath Ghosal
AU  - Robert P. Gunsalus
AU  - Grant J. Jensen
TI  - Structure of the archaellar motor and associated cytoplasmic cone in <em>Thermococcus kodakaraensis</em>
AID  - 10.1101/108209
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 108209
4099  - http://biorxiv.org/content/early/2017/02/13/108209.short
4100  - http://biorxiv.org/content/early/2017/02/13/108209.full
AB  - Archaeal swimming motility is driven by rotary motors called archaella. The structure of these motors, and particularly how they are anchored in the absence of a peptidoglycan cell wall, is unknown. Here, we use electron cryotomography to visualize the archaellar motor in vivo in Thermococcus kodakaraensis. Compared to the homologous bacterial type IV pilus (T4P), we observe structural similarities as well as several unique features. While the position of the cytoplasmic ATPase appears conserved, it is not braced by linkages that extend upward through the cell envelope as in the T4P, but rather by cytoplasmic components that attach it to a large conical frustum up to 500 nm in diameter at its base. In addition to anchoring the lophotrichous bundle of archaella, the conical frustum associates with chemosensory arrays and ribosome-excluding material and may function as a polar organizing center for the coccoid cells.