BIOCHEMISTRY. For the article “Cracks in the β-can: Fluorescent proteins from Anemonia sulcata (Anthozoa, Actinaria),” by Jörg Wiedenmann, Carsten Elke, Klaus-Dieter Spindler, and Werner Funke, which appeared in number 26, December 19, 2000, of Proc. Natl. Acad. Sci. USA (97, 14091–14096), the authors note the following. The proposed truncated form of the β-can is withdrawn. This correction concerns our work on the GFP homologs asCP562 and asFP595 from A. sulcata. Another group cloned a nonfluorescent red protein initially named asFP595 from another color morph of A. sulcata (1) [most likely A. sulcata var. vulgaris (2)], but changed recently to asCP/asulCP (3). This protein fluoresces with a minimal quantum yield. The cyclization mechanism for the chromophore of this protein (4) includes a cleavage of the peptide backbone and fragmentation of the protein upon denaturation. The authors reported that the truncation of the recombinant protein we suggested in our paper does not yield a functional protein.
Repeated sequencing of asCP562 revealed an error suggesting a shortened open reading frame. The sequence of asCP562 has been corrected under the published accession no. (AF322222). The sequence shows a high similarity to the sequence published by Martynov and coworkers (3) (see Fig. 1 A and B). Purified recombinant asCP562 yielded the same fragmentation pattern as asulCP. These new results indicate that asCP562 and highly fluorescent asFP595 are formed in the way described for asulCP (asFP595; ref. 1). For these reasons, the proposed truncated form of the β-can is not valid.
Figure 1.
(A) Nucleotide sequence alignment of the regions coding for asFP595 (ref. 1) and asCP562. Differing residues are bold and underlined. (B) Amino acid sequence alignment of asFP595 (ref. 1) and asCP562. Differing residues are bold and underlined.
The corrected sequences were provided by B. Sundin, Department of Biochemistry, University of Washington, and G. Jach, Max-Planck-Institut für Züchtungsforschung, Köln, Germany.
1. Lukyanov, K. A., Fradkov, A. F., Gurskaya, N. G., Matz, M. V., Labas, Y. A., Savitsky, A. P., Markelov, M. L., Zaraisky, A. G., Zhao, X., Fang, Y., Tan, W. & Lukyanov, S. A. (2000) J. Biol. Chem. 275, 25879–25882. 2. Wiedenmann, J., Röcker, C. & Funke, W. (1999) in Verhandlungen der Gesellschaft für Ökologie, ed. Pfadenhauer, J. (Spektrum Akademischer, Berlin), Band 29, pp. 497–503. 3. Labas, Y. A., Gurskaya, N. G., Yanushevich, Y. G., Fradkov, A. F., Lukyanov, K. A., Lukyanov, S. A. & Matz, M. V. (2002) Proc. Natl. Acad. Sci. USA 99, 4256–4261. 4. Martynov, V. I., Savisky, A. P., Martynova, A. Y., Savitsky, P. A., Lukyanov, K. A. & Lukyanov, S. A. (2001) J. Biol. Chem. 276, 21012–21016.