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D Neuhaus

Publications and source records attributed to D Neuhaus.

46 records · Page 3Linked to original sources

Solution structure of the DNA-binding domain of the oestrogen receptor.

Steroid hormone receptors control gene expression through binding, as dimers, to short palindromic response elements located upstream of the genes they regulate. An independent domain of approximately 70 amino acids directs this sequence-specific DNA binding and is highly conserved between different receptor proteins and related transcription factors. This domain contains two zinc-binding Cys2-Cys2 sequence motifs, which loosely resemble the 'zinc-finger' motifs of TFIIIA. Here we describe the structure of the DNA-binding domain from the oestrogen receptor, as determined by two-dimensional 1H NMR techniques. The two 'zinc-finger'-like motifs fold to form a single structural domain and are thus distinct from the independently folded units of the TFIIIA-type zinc fingers. The structure consists of two helices perpendicular to each other. A zinc ion, coordinated by four conserved cysteines, holds the base of a loop at the N terminus of each helix. This novel structural domain seems to be a general structure for protein-DNA recognition.

Amino Acid Sequence↗

Sequence-specific [1H]NMR resonance assignments and secondary structure identification for 1- and 2-zinc finger constructs from SW15. A hydrophobic core involving four invariant residues.

Complete [1H]NMR resonance assignments are presented for the second of the three zinc fingers from SW15 as it appears in both 1- and 2-finger constructs. Signals from finger 2 are unaffected by the presence or absence of finger 1, showing that the protein has a modular construction. The structure of finger 2 comprises a helix running from N56 to Q67, and a region approximating to an anti-parallel beta-sheet running from Y42 to F53. These features combine to produce a hydrophobic core in the structure involving the invariant residues Y42, F53, L59 and H62.

Amino Acid Sequence↗

Spatial structure of rabbit liver metallothionein-2 in solution by NMR.

Sequence-specific assignments of the proton spin systems of (Cd7) rabbit liver metallothionein-2 were obtained with homonuclear two-dimensional nuclear magnetic resonance techniques. On the basis of the NMR data the amino acid sequence had to be modified in six positions, and it was found that the protein consists of 62 rather than 61 residues. Through-bond connectivities between the metals and sequentially assigned cysteine residues were obtained with two-dimensional heteronuclear 1H-113Cd correlated spectroscopy. This information, and distance constraints obtained from nuclear Overhauser enhancement spectra were used as input for distance geometry calculations of the spatial polypeptide fold. The polypeptide chain forms two domains which enclose a three-metal cluster and a four-metal cluster, respectively. The metal coordination within the clusters is markedly different from that of (Cd5, Zn2)-MT-2 from rat liver as determined by X-ray crystallography (Furey, et al., 1986) i.e. in the two structures different metal-cysteine combinations prevail for 5 of the 12 connectivities in the three-metal cluster and for 14 of the 16 connectivities in the four-metal cluster.

Amino Acid Sequence↗

Sequence-specific 1H-NMR assignments in rabbit-liver metallothionein-2.

The complete sequence-specific assignment of the 1H nuclear magnetic resonance spectrum of a major subform of rabbit liver metallothionein-2 is presented. The sequential assignment procedures revealed a number of differences with regard to results obtained by earlier partial chemical sequencing of a preparation now known to be microheterogeneous. In particular, the present data indicate a polypeptide chain length of 62 amino acid residues as compared to the occurrence of 61 amino acids in all other known mammalian metallothioneins. In the new sequence, which was also fully confirmed by chemical means, the additional amino acid residue was identified as Ala8' inserted between Ala8 and Ala9 of the standard amino acid numeration. In addition to the predominant protein species all preparations contained a minor component, for which the two-dimensional 1H-nuclear magnetic resonance features are compatible with a chemically different, homologous metallothionein.

Amino Acid Sequence↗

Nuclear magnetic resonance identification of "half-turn" and 3(10)-helix secondary structure in rabbit liver metallothionein-2.

Analysis of 1H-1H nuclear Overhauser effects and amide proton-C alpha proton coupling constants in rabbit liver metallothionein-2 resulted in the identification of two segments of 3(10)-helix and numerous secondary structure elements of a novel type, which we call "half-turn". A half-turn can be generated starting from a type II tight turn by rotation of phi 3 from +90 degrees to -90 degrees. Its appearance in metallothionein appears to be a consequence of the constraints on the polypeptide conformation by the large number of metal binding sites.

Animals↗

Systematic application of high-resolution, phase-sensitive two-dimensional 1H-NMR techniques for the identification of the amino-acid-proton spin systems in proteins. Rabbit metallothionein-2.

Novel strategies for elucidation and classification of amino acid 1H-NMR spin systems in proteins were developed exploiting recently introduced two-dimensional NMR techniques such as phase-sensitive double-quantum-filtered correlated spectroscopy, relayed coherence transfer spectroscopy, double quantum spectroscopy and nuclear Overhauser spectroscopy. Due to the improved resolution in phase-sensitive spectra, the fine structure of cross peaks could be exploited as a powerful source of information for establishing 1H-1H connectivities. Principles for the interpretation of multiplet structures of absorption mode cross peaks are discussed. With these methods the 1H spin systems of rabbit liver metallothionein-2 were elucidated and classified according to amino acid types. Despite the intrinsically difficult situation arising from the unusual amino acid composition of this protein, a more complete characterization of the 1H spin systems prior to the step of sequential resonance assignments was achieved with the presently introduced methodology than was possible in earlier studies of proteins of similar size.

Amino Acids↗

113CD-1H spin-spin couplings in homonuclear 1H correlated spectroscopy of metallothionein. Identification of the cysteine 1H spin systems.

Heteronuclear spin-spin couplings between 113Cd and C beta protons of the metal-bound cysteines were observed in phase-sensitive, double-quantum filtered, homonuclear two-dimensional correlated (COSY) 1H NMR spectra of 113Cd-metallothionein-2 from rabbit liver. Comparison of 113Cd- and 112Cd-metallothionein-2 spectra revealed that 19 1H spin systems show heteronuclear couplings to at least one 113Cd and were thus identified as 19 of the 20 cysteines in this protein. From a detailed analysis of the manifestations of heteronuclear couplings in the homonuclear 1H COSY spectra, two cysteines could be identified as 'bridging cysteines', with spin-spin couplings to two different 113Cd nuclei. The observed 113Cd-1H coupling constants vary between less than or equal to 5 Hz and 80 Hz.

Animals↗