The structural basis for red fluorescence in the tetrameric GFP homolog DsRed.
Green fluorescent protein (GFP) has rapidly become a standard tool for investigating a variety of cellular activities, and has served as a model system for understanding spectral tuning in chromophoric proteins. Distant homologs of GFP in reef coral and anemone display two new properties of the fluorescent protein family: dramatically red-shifted spectra, and oligomerization to form tetramers. We now report the 1.9 A crystal structure of DsRed, a red fluorescent protein from Discosoma coral. DsRed monomers show similar topology to GFP, but additional chemical modification to the chromophore extends the conjugated pi-system and likely accounts for the red-shifted spectra. Oligomerization of DsRed occurs at two chemically distinct protein interfaces to assemble the tetramer. The DsRed structure reveals the chemical basis for the functional properties of red fluorescent proteins and provides the basis for rational engineering of this subfamily of GFP homologs.
Wall
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Howard Hughes Medical Institute, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390-9050, USA.
Socolich
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Ranganathan
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D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003063:Cnidaria / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005453:Fluorescence; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C413663:fluorescent protein 583; D049452:Green Fluorescent Proteins