title: NMR spin state exchange spectroscopy reveals equilibrium of two distinct conformations of leucine zipper GCN4 in solution.
abstract: The resonance assignment, secondary structure, and dynamic properties of a stable noncoiled coil conformation of the dimerization domain from yeast transcription activation factor GCN4 (Leu zipper; LZGCN4) are presented. Introduced in this paper, a new line of fully optimized spin state exchange experiments, XYEX-TROSY, applied to 1HN, 15N and 1Halpha,13Calpha moieties, established that in broad range of pH and buffer conditions the classical LZGCN4 coiled coil dimer is in a dynamic equilibrium with another distinct conformation (denoted here as x-form) and enabled complete assignment of the resonances stemming from the x-form. The LZGCN4 x-form is generally less structured in comparison with the classical GCN4-p1 coiled coil, but still retains a structured alpha-helical central core. The implications for folding properties and biological significance are discussed.
authors.affiliation: Laboratory of Physical Chemistry, Swiss Federal Institute of Technology (ETH Zurich), CH-8093 Zurich, Switzerland.
authors.forename: Yaroslav
authors.initials: Y
authors.lastname: Nikolaev
authors.forename: Konstantin
authors.initials: K
authors.lastname: Pervushin
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D016350:Leucine Zippers; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012996:Solutions; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C501391:GCN4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D012996:Solutions; D014157:Transcription Factors