Nat. Struct. Mol. Biol. 11, 1237–1242 (2004). The manuscript contained a description of, as well as data and conclusions derived from, a U2–U6 RNA (the 110-nucleotide RNA) that was conceived, created and supplied by C. Joel McManus (C.J.M.) and David A. Brow (D.A.B.). Although C.J.M. was acknowledged in the original version, both C.