Nature 438, 633–638 (2005)

We wish to clarify that we calculated the G factor of -1.5 with the initially deposited coordinates for non-junctional AQP0, 1TM8, and not with 1YMG as stated in this Article, which replaced 1TM8 (January 2005) and which has a G factor of 0.3. Also, we did not deposit the structure factors for the X-ray structure of non-junctional AQP0 at the Protein Data Bank, as indicated in the Author Information section: in fact, we deposited our alternative modelling of non-junctional AQP0 (PDB accession number is 2B6P).