title: Sequence-specific 1H-NMR assignment and secondary structure of the Tyr41----His mutant of the single-stranded DNA binding protein, gene V protein, encoded by the filamentous bacteriophage M13.
abstract: Sequence-specific 1H-NMR assignments are reported for the Tyr41----His (Y41H) mutant of the single-stranded DNA binding protein, encoded by gene V of the filamentous bacteriophage M13 (GVP). The mutant protein was chosen for this purpose because it exhibits significantly improved solubility characteristics over wild-type GVP [Folkers et al. (1991) Eur. J. Biochem. 200, 139-148]. The secondary structure elements present in the protein are deduced from a qualitative interpretation of the nuclear Overhauser enhancement spectra and amide exchange data. The protein is entirely composed of antiparallel beta-structure. It is shown that identical structural elements are present in wild-type GVP. Previously, we have demonstrated that the secondary structure of the beta-loop, encompassing residues 13-31 which is present in GVP in solution, deviates from that proposed for the same amino acid sequence on the basis of X-ray diffraction data [van Duynhoven et al. (1990) FEBS Lett. 261, 1-4]. Now that we have arrived at a complete description of the secondary structure of the protein in solution, other deviations with respect to the crystallographically determined structure became apparent as well. The N-terminal part of the protein is, in solution, part of a triple-stranded beta-sheet while, in the crystal, it is an extended strand pointing away from the bulk of the protein dimer. One of the antiparallel beta-sheets in the protein which had been designated earlier as the complex loop has, in the solution structure, a different pairwise arrangement of the residues in its respective beta-ladders. Residues 30 and 48 are opposite to one another in the solution structure while in the crystal structure residues 32 and 48 are paired. A similar observation is made for the so-called dyad domain of the protein of which the beta-sheet in the solution structure is shifted by one residue with respect to that of the crystal structure.
authors.affiliation: Nijmegen SON Research Center, University of Nijmegen, The Netherlands.
authors.forename: P J
authors.initials: PJ
authors.lastname: Folkers
authors.forename: J P
authors.initials: JP
authors.lastname: van Duynhoven
authors.forename: A J
authors.initials: AJ
authors.lastname: Jonker
authors.forename: B J
authors.initials: BJ
authors.lastname: Harmsen
authors.forename: R N
authors.initials: RN
authors.lastname: Konings
authors.forename: C W
authors.initials: CW
authors.lastname: Hilbers
mesh_terms: D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D005814:Genes, Viral; D006639:Histidine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009154:Mutation; D011487:Protein Conformation; D014443:Tyrosine / Q000737:chemistry*; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics; D014961:X-Ray Diffraction
chemical_list: D004268:DNA-Binding Proteins; D014764:Viral Proteins; C057816:gene 5 protein, Enterobacteria phage M13; D014443:Tyrosine; D006639:Histidine