Archaellum Structure Graphical Abstract (image) DOE/Lawrence Berkeley National Laboratory Caption Individual FlaI proteins have two units, bases and points, connected by a flexible linker. When bound to ATP they assemble a six-member crown, which attaches to the base of the FlaJ protein in the cell membrane. When an individual FlaI proteon hydrolyzes ATP and releases a phosphate, its point moves up and creates a space beneath the archaellum filament, where FlaB subunits can join the filament's base, causing it to grow. The same changes in conformation drive rotation, but the exact mechanism is still be learned. Credit Reindl et al, Berkeley Lab and MPI Usage Restrictions with credit as given Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.