Solution structure of the active domain of tissue inhibitor of metalloproteinases-2. A new member of the OB fold protein family

• Published in: Biochemistry (Easton) Vol. 33; no. 39; pp. 11745 - 11759
• Main Authors: Williamson, Richard A, Martorell, Gabriel, Carr, Mark D, Murphy, Gillian, Docherty, Andrew J. P, Freedman, Robert B, Feeney, James
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.10.1994
• Subjects: Amino Acid Sequence; Binding Sites; Magnetic Resonance Spectroscopy - methods; Metalloendopeptidases - antagonists & inhibitors; Models, Molecular; Molecular Sequence Data; Peptide Fragments - chemistry; Protein Conformation; Protein Structure, Secondary; Proteins - chemistry; Proteins - classification; Recombinant Proteins - chemistry; Sequence Homology, Amino Acid; Solutions - chemistry; Tissue Inhibitor of Metalloproteinase-2
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi00205a010

Homonuclear two-dimensional and three-dimensional 1H nuclear magnetic resonance spectroscopy has been used to obtain essentially complete sequence-specific assignments for 123 of the 127 amino acid residues present in the truncated form of tissue inhibitor of metalloproteinases-2 (delta TIMP-2), the active N-terminal domain of the protein. Analysis of the through-space nuclear Overhauser effect data obtained for delta TIMP-2 allowed determination of both the secondary structure of the domain and also a low-resolution tertiary structure defining the protein backbone topology. The protein contains a five-stranded antiparallel beta-sheet that is rolled over on itself to form a closed beta-barrel, and two short helices which pack close to one another on the same barrel face. A comparison of the delta TIMP-2 structure with other known protein folds reveals that the beta-barrel topology is homologous to that seen in proteins of the oligosaccharide/oligonucleotide binding (OB) fold family. The common structural features include the number of beta-strands and their arrangement, the beta-barrel shear number, an interstrand hydrogen bond network, the packing of the hydrophobic core, and a conserved beta-bulge. Superpositions of the beta-barrels from delta TIMP-2 and two previously known members of the OB protein fold family (staphylococcal nuclease and Escherichia coli heat-labile enterotoxin) confirmed the similarity in beta-barrel topology. The three-dimensional structure of delta TIMP-2 has allowed a more detailed interpretation than was previously possible of the functional significance of available protein sequence and site-directed mutagenesis data for the TIMP family. Furthermore, the structure has revealed conserved surface regions of potential functional importance.