title: Crystal structure of the beta-chain of human hepatocyte growth factor-like/macrophage stimulating protein.
abstract: Hepatocyte growth factor like/macrophage stimulating protein (HGFl/MSP) and hepatocyte growth factor/scatter factor (HGF/SF) define a distinct family of vertebrate-specific growth factors structurally related to the blood proteinase precursor plasminogen and with important roles in development and cancer. Although the two proteins share a similar domain structure and mechanism of activation, there are differences between HGFl/MSP and HGF/SF in terms of the contribution of individual domains to receptor binding. Here we present a crystal structure of the 30 kDa beta-chain of human HGFl/MSP, a serine proteinase homology domain containing the high-affinity binding site for the RON receptor. The structure describes at 1.85 Angstrom resolution the region of the domain corresponding to the receptor binding site recently defined in the HGF/SF beta-chain, namely the central cleft harboring the three residues corresponding to the catalytic ones of active proteinases (numbers in brackets define the sequence position according to the standard chymotrypsinogen numbering system) [Gln522 (c57), Gln568 (c102) and Tyr661 (c195)] and an adjacent loop flanking the S1 specificity pocket and containing residues Asn682 (c217) and Arg683 (c218) previously shown to be essential for binding of HGFl/MSP to the RON receptor. The study confirms the concept that the serine proteinase homology domains of HGFl/MSP and HGF/SF bind their receptors in an 'enzyme-substrate' mode, reflecting the common evolutionary origin of the plasminogen-related growth factors and the proteinases of the clotting and fibrinolytic pathways. However, analysis of the intermolecular interactions in the crystal lattice of beta-chain HGFl/MSP fails to show the same contacts seen in the HGF/SF structures and does not support a conserved mode of dimerization of the serine proteinase homology domains of HGFl/MSP and HGF/SF responsible for receptor activation.
authors.affiliation: MRC Centre, Hills Road, Cambridge, UK.
authors.forename: Federico
authors.initials: F
authors.lastname: Carafoli
authors.forename: Dimitri Y
authors.initials: DY
authors.lastname: Chirgadze
authors.forename: Tom L
authors.initials: TL
authors.lastname: Blundell
authors.forename: Ermanno
authors.initials: E
authors.lastname: Gherardi
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D017228:Hepatocyte Growth Factor / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction
chemical_list: C066855:HGF protein, human; D017228:Hepatocyte Growth Factor; C080835:RON protein; D020794:Receptor Protein-Tyrosine Kinases