A photoswitchable DNA-binding protein based on a truncated GCN4-photoactive yellow protein chimera.
Photo-controlled DNA-binding proteins promise to be useful tools for probing complex spatiotemporal patterns of gene expression in living organisms. Here we report a novel photoswitchable DNA-binding protein, GCN4(S)Δ25PYP, based on a truncated GCN4-photoactive yellow protein chimera. In contrast to previously reported designed photoswitchable proteins where DNA binding affinity is enhanced upon irradiation, GCN4(S)Δ25PYP dissociates from DNA when irradiated with blue light. In addition, the rate of thermal relaxation to the ground state, part of the PYP photocycle, is enhanced by DNA binding whereas in previous reported constructs it is slowed. The origins of this reversed photoactivity are analyzed in structural terms.
Morgan
Stacy-Anne
SA
Department of Chemistry, University of Toronto, 80 St. George St., Toronto, ON M5S 3H6, Canada.
Woolley
G Andrew
GA
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D020283:Photoreceptors, Microbial / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet
D001426:Bacterial Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C501391:GCN4 protein, S cerevisiae; D020283:Photoreceptors, Microbial; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C050162:photoactive yellow protein, Bacteria; D004247:DNA