Variations on the GFP Chromophore

• Published in: The Journal of biological chemistry Vol. 280; no. 4; pp. 2401 - 2404
• Main Authors: Wilmann, Pascal G., Petersen, Jan, Devenish, Rodney J., Prescott, Mark, Rossjohn, Jamie
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 28.01.2005; American Society for Biochemistry and Molecular Biology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.C400484200

We have determined to 2.1 Å resolution the crystal structure of a dark state, kindling fluorescent protein isolated from the sea anemone, Anemonia sulcata. The chromophore sequence Met63-Tyr64-Gly65 of the A. sulcata chromoprotein was previously proposed to comprise a 6-membered pyrazine-type heterocycle (Martynov, V. I., Savitsky, A. P., Martynova, N. Y., Savitsky, P. A., Lukyanov, K. A., and Lukyanov, S. A. (2001) J. Biol. Chem. 276, 21012–21016). However, our crystallographic data revealed the chromophore to comprise a 5-membered p-hydroxybenzylideneimidazolinone moiety that adopts a non-coplanar trans conformation within the interior of the GFP β-can fold. Unexpectedly, fragmentation of the polypeptide was found to occur within the chromophore moiety, at the bond between Cys62C and Met63N1. Our structural data reveal that fragmentation of the chromophore represents an intrinsic, autocatalytic step toward the formation of the mature chromophore within the specific GFP-like proteins.