Nat. Chem. Biol. 2, 87–94 (2006)

In the print version of this article and the version initially published online, the subsection “Estimation of tetramer dissociation” of the Methods contained an error. The second sentence should read: “To determine the timescale of tetramer dissociation, we recorded the enzymatic activity, as a function of time, of 20 pM of biotin-linked β-galactosidase immobilized on 1-μm-diameter streptavidin-coated beads present in excess”. The error has been corrected in the HTML and PDF versions of the article. This correction has been appended to the PDF version.