gkm819 7041..7041 Published online 11 October 2007 Nucleic Acids Research, 2007, Vol. 35, No. 20 7041 doi:10.1093/nar/gkm819 ERRATUM Post-transcriptional nucleotide modification and alternative folding of RNA Mark Helm Nucleic Acids Res., (2006) 34, 721–733 The author wishes it to be known that there was a print error in Figure 4 of the above mentioned article. A corrected figure is shown below with its legend. Figure 4. Rearrangement on the secondary structure level induced by double methylation of human cytosolic tRNAAsn. The calculated structure of the unmodified transcript on the left side features an aberrant D-stem without G10, but including G26. Double methylation on N6 of G26 impedes its Watson–Crick pairing with Cytidines and thus renders the base pair G26-C11, which is highlighted by a box, impossible. The fully modified tRNAAsn may thus adopt the classical cloverleaf structure as shown on the right. U? denoted an unknown modified uridine, likely a derivative of ribothymidine, at position 54. � 2007 The Author(s) This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.