Nat. Struct. Mol. Biol. 15, 452–461 (2008); published online 4 May; corrected after print 15 May 2008

In the version of this article initially published, the concentration units reported in Figure 7b,c should be nM, not nm. The green data series in Figure 7b should be labeled “SOScat”. The corrected figure panels are shown below:

In addition, on page 452 of the article, the affiliation address for William J. Galush and Jay T. Groves was incorrect. Their correct address is Department of Chemistry, University of California, Berkeley, California 94720, USA. Finally, the last sentence of the Acknowledgments listed incorrect funding information. The last sentence should read, “J.T.G. and W.J.G. are supported by Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences of the US Department of Energy under Contract No. DE_AC03-76SF00098, and D.B.-S. by NIH GM078266.” These errors have been corrected in the HTML and PDF versions of the article.