title: Solution structure of the transforming growth factor beta-binding protein-like module, a domain associated with matrix fibrils.
abstract: Here we describe the high resolution nuclear magnetic resonance (NMR) structure of a transforming growth factor beta (TGF-beta)-binding protein-like (TB) domain, which comes from human fibrillin-1, the protein defective in the Marfan syndrome (MFS). This domain is found in fibrillins and latent TGF-beta-binding proteins (LTBPs) which are localized to fibrillar structures in the extracellular matrix. The TB domain manifests a novel fold which is globular and comprises six antiparallel beta-strands and two alpha-helices. An unusual cysteine triplet conserved in the sequences of TB domains is localized to the hydrophobic core, at the C-terminus of an alpha-helix. The structure is stabilized by four disulfide bonds which pair in a 1-3, 2-6, 4-7, 5-8 pattern, two of which are solvent exposed. Analyses of MFS-causing mutations and the fibrillin-1 cell-binding RGD site provide the first clues to the surface specificity of TB domain interactions. Modelling of a homologous TB domain from LTBP-1 (residues 1018-1080) suggests that hydrophobic contacts may play a role in its interaction with the TGF-beta1 latency-associated peptide.
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
authors.forename: X
authors.initials: X
authors.lastname: Yuan
authors.forename: A K
authors.initials: AK
authors.lastname: Downing
authors.forename: V
authors.initials: V
authors.lastname: Knott
authors.forename: P A
authors.initials: PA
authors.lastname: Handford
mesh_terms: D000595:Amino Acid Sequence; D002448:Cell Adhesion; D005109:Extracellular Matrix; D000071838:Fibrillin-1; D000071837:Fibrillins; D006801:Humans; D008382:Marfan Syndrome; D008840:Microfilament Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D016212:Transforming Growth Factor beta; D054392:Adipokines
chemical_list: D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D012996:Solutions; D016212:Transforming Growth Factor beta; C000605722:FBN1 protein, human; D054392:Adipokines