Figure 1.

Schematic model of the S . acidocaldarius archaellum.

A. The pre‐archaellin FlaB is processed by the peptidase PibD/FlaK and then assembled into the archaellum filament, which is a three start helical filament. The motor complex is formed by the ring‐forming scaffold protein FlaX in which FlaH and FlaI probably interact with the integral membrane protein FlaJ. The dimeric soluble domain of FlaF interacts with the S‐layer. FlaG most probably has a similar function as FlaF as its soluble domain has homologies to FlaF.

B. Operons encoding the archaellum in S . acidocaldarius and P . furiosus. Genes have the same color as the respective proteins in (A).