There was an error published in J. Cell Sci. 124, 2515-2519.

In the poster that accompanied this article the centre panel, entitled ‘Structural and functional features’ contains the sub-panel ‘Energy coupling’ in which the bottom structure should not be labelled ‘E1P open’ but ‘E2P open’.

The correct version of this panel is as follows:

The correct version of the poster is available for downloading at http://jcs.biologists.org/content/124/2/157/suppl/DC2

The authors apologise for this error.