9.B.461. The ATP-driven Rotary Archaellum (ARA) Family Motile archaea swim by means of a molecular machine called the archaellum (Nuno de Sousa Machado et al. 2022). This structure consists of a filament attached to a membrane-embedded motor. The archaellum is found exclusively in members of the archaeal domain, but the core of its motor shares homology with the motor of type IV pili (T4P). Nuno de Sousa Machado et al. 2022 provided an overview of the different components of the archaellum machinery and hypothetical models to explain how rotary motion of the filament is powered by the archaellum motor. The history or archaeal motility studies has been summarized (Jarrell et al. 2021).
References:
Jarrell, K.F., S.V. Albers, and J.N.S. Machado. (2021). A comprehensive history of motility and Archaellation in Archaea. FEMS Microbes 2: xtab002.
Nuno de Sousa Machado, J., S.V. Albers, and B. Daum. (2022). Towards Elucidating the Rotary Mechanism of the Archaellum Machinery. Front Microbiol 13: 848597.
Examples:
TC#	Name	Organismal Type	Example
9.B.461.1.1	Multi-component rotary archaellum, consisting of at least eight protein constituents, ArlAl (213 aas; 1 N-terminal TMS; archaellinA1), ArlA2 (220 aas; 1 N-terminal TMS; archaellinA2), AlrD (176 aas; archaellin D; may be N-terminally truncated; 0 TMSs), ArlF (145 aas; 1 N-terminal TMS), ArlG (149 aas), ArlH (249 aas with possibly 4 or 5 moderately hydrophobic TMSs), ArlI (554 aas, 0 TMSs), and ArlJ (580 aas and 0 TMSs). These last two proteins may function as the motor (Nuno de Sousa Machado et al. 2022).		The multi-component archaellum of Haloferax volcanii. ArlA1, ADE02581.1 ArlA2, ADE03249.1 ArlD, ADE02570.1 ArlF, ADE04571.1 ArlG, ADE02944.1 ArlH, ADE03231.1 ArlI, ADE03872.1 ArlJ, ADE03175.1