title: Conformational response to ligand binding in phosphomannomutase2: insights into inborn glycosylation disorder.
abstract: The most common glycosylation disorder is caused by mutations in the gene encoding phosphomannomutase2, producing a disease still without a cure. Phosphomannomutase2, a homodimer in which each chain is composed of two domains, requires a bisphosphate sugar (either mannose or glucose) as activator, opening a possible drug design path for therapeutic purposes. The crystal structure of human phosphomannomutase2, however, lacks bound substrate and a key active site loop. To speed up drug discovery, we present here the first structural model of a bisphosphate substrate bound to human phosphomannomutase2. Taking advantage of recent developments in all-atom simulation techniques in combination with limited and site-directed proteolysis, we demonstrated that α-glucose 1,6-bisphosphate can adopt two low energy orientations as required for catalysis. Upon ligand binding, the two domains come close, making the protein more compact, in analogy to the enzyme in the crystals from Leishmania mexicana. Moreover, proteolysis was also carried out on two common mutants, R141H and F119L. It was an unexpected finding that the mutant most frequently found in patients, R141H, although inactive, does bind α-glucose 1,6-bisphosphate and changes conformation.
authors.affiliation: From the Istituto di Chimica Biomolecolare-Consiglio Nazionale Delle Ricerche, 80078 Pozzuoli, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Andreotti
authors.affiliation: Joint Barcelona Supercomputing Center-Center for Genomic Regulation-Institute for Research in Biomedicine Research Program in Computational Biology, Barcelona Supercomputing Center, c/Jordi Girona 29, 08034 Barcelona, Spain.
authors.forename: Israel
authors.initials: I
authors.lastname: Cabeza de Vaca
authors.affiliation: From the Istituto di Chimica Biomolecolare-Consiglio Nazionale Delle Ricerche, 80078 Pozzuoli, Italy, Dipartimento di Biologia, Università Federico II, 80126 Naples, Italy.
authors.forename: Angelita
authors.initials: A
authors.lastname: Poziello
authors.affiliation: Dipartimento di Farmacia, Università degli Studi di Salerno, 84084 Fisciano, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Monti
authors.affiliation: Joint Barcelona Supercomputing Center-Center for Genomic Regulation-Institute for Research in Biomedicine Research Program in Computational Biology, Barcelona Supercomputing Center, c/Jordi Girona 29, 08034 Barcelona, Spain, Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain, and victor.guallar@bsc.es.
authors.forename: Victor
authors.initials: V
authors.lastname: Guallar
authors.affiliation: Dipartimento di Biologia, Università Federico II, 80126 Naples, Italy cubellis@unina.it.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Cubellis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D008024:Ligands; D008661:Metabolism, Inborn Errors / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010447:Peptide Hydrolases / Q000378:metabolism; D017875:Phosphotransferases (Phosphomutases) / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D058767:Protein Unfolding; D059748:Proteolysis; D013696:Temperature
chemical_list: D008024:Ligands; D019298:Glucose-6-Phosphate; C016473:glucose-1,6-bisphosphate; D010447:Peptide Hydrolases; D017875:Phosphotransferases (Phosphomutases); C519582:phosphomannomutase 2, human
keywords: 1,6-Bisphosphate; Computer Modeling; Drug Discovery; Glycosylation; Glycosylation Inhibitor; Ligand-binding Protein; PELE; Phosphomannomutase