Nat. Struct. Mol. Biol. 12, 663–653 (2005).

The manuscript contained an error in the name of one of the authors. Maciej Gajec was misspelled Maciez Gajek. The correct author list should read: Barbara A L Owen, Zungyoon Zang, Maoyi Lai, Maciej Gajec, John D Badger II, Jeffrey J Hayes, Winfried Edelmann, Raju Kucherlapati, Teresa M Wilson & Cynthia T McMurray.