Abstract
While bacteria employ the flagellum for swimming motility it has become apparent that archaea possess an evolutionary not related motility structure termed archaellum. The archaellum structurally resembles type IV pili, but in contrast to all described type IV pili it rotates, thereby propelling archaeal cells forward at the same speed as flagella do with bacteria.
The archaellum of the hyperthermophilic Sulfolobus acidocaldarius consists of only seven subunits and therefore is a great model system for understanding the assembly pathway and its mechanism of rotation. All seven subunits are essential for the assembly of the S. acidocaldarius archaellum and I will present the biochemical and structural data that we have obtained so far to understand their function in the assembly and rotation of the archaellum. Furthermore, insights into how protein phosphorylation influences the regulation of archaellum biosynthesis will be discussed.