title: 1H, 15N and 13C NMR assignments of the 434 repressor fragments 1-63 and 44-63 unfolded in 7 M urea.
abstract: An E. coli overexpression system for the N-terminal domain of the 434 repressor with residues 1-63 (434 repressor(1-63)) was constructed and used to produce this polypeptide with uniform 15N-labeling, and with 13C-labeling of the methyl groups of valine and leucine. Using these protein preparations almost complete sequence-specific resonance assignments were obtained for the urea-unfolded form of the 434 repressor(1-63). In addition, the isotope-labeled tryptic peptide, 44-63, was produced by enzymatic cleavage of the recombinant 434 repressor(1-63), and its NMR spectrum was assigned. Corresponding residues in 434 repressor(1-63) and 434 repressor(44-63) in 7 M urea were found to have nearly identical chemical shifts, and in both species similar deviations from 1H random coil shifts were found as previously in 434 repressor(1-69). These indicate the presence of residual non-random structure in the polypeptide segment 50-60. The present NMR assignments, which include stereospecific assignments for the diastereotopic methyl groups of Val and Leu, are the basis for detailed studies of this residual structure in the urea-unfolded form of the 434 repressor.
authors.affiliation: Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, Zürich, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Neri
authors.forename: G
authors.initials: G
authors.lastname: Wider
authors.forename: K
authors.initials: K
authors.lastname: Wüthrich
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics; D014508:Urea / Q000737:chemistry*; D014764:Viral Proteins
chemical_list: C063367:434-repressor protein, Bacteriophage 434; D004269:DNA, Bacterial; D012097:Repressor Proteins; D014764:Viral Proteins; D014508:Urea