Han Remaut, Coralie Bompard-Gilles, Colette Goffin, Jean-Maire Frère and Jozef Van Beeumen Nature Struct. Biol. 8, 674–678 (2001).

Part of the reference list was incorrectly printed in this paper. The first ref. 12 in the list should be renumbered as ref. 11; the original ref. 11 in the list should be deleted. The citation of these references in the text corresponds to the corrected numbering scheme. Citations for MLPHARE and DM in footnotes 2 and 3 of Table 1 were also incorrectly printed. The correct citation for both is ref. 27. We apologize for any confusion these may have caused.