title: A sequence-specific transcription activator motif and powerful synthetic variants that bind Mediator using a fuzzy protein interface.
abstract: Although many transcription activators contact the same set of coactivator complexes, the mechanism and specificity of these interactions have been unclear. For example, do intrinsically disordered transcription activation domains (ADs) use sequence-specific motifs, or do ADs of seemingly different sequence have common properties that encode activation function? We find that the central activation domain (cAD) of the yeast activator Gcn4 functions through a short, conserved sequence-specific motif. Optimizing the residues surrounding this short motif by inserting additional hydrophobic residues creates very powerful ADs that bind the Mediator subunit Gal11/Med15 with high affinity via a "fuzzy" protein interface. In contrast to Gcn4, the activity of these synthetic ADs is not strongly dependent on any one residue of the AD, and this redundancy is similar to that of some natural ADs in which few if any sequence-specific residues have been identified. The additional hydrophobic residues in the synthetic ADs likely allow multiple faces of the AD helix to interact with the Gal11 activator-binding domain, effectively forming a fuzzier interface than that of the wild-type cAD.
authors.affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and.
authors.forename: Linda
authors.initials: L
authors.lastname: Warfield
authors.affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and Department of Biochemistry, University of Washington, Seattle, WA 98195.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Tuttle
authors.affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and.
authors.forename: Derek
authors.initials: D
authors.lastname: Pacheco
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, WA 98195 klevit@u.washington.edu shahn@fhcrc.org.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Klevit
authors.affiliation: Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and klevit@u.washington.edu shahn@fhcrc.org.
authors.forename: Steven
authors.initials: S
authors.lastname: Hahn
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D056892:Mediator Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; C058337:GAL11 protein, S cerevisiae; C501391:GCN4 protein, S cerevisiae; D056892:Mediator Complex; D046912:Multiprotein Complexes; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins
keywords: Mediator complex; protein NMR