title: Towards the identification of the allosteric Phe-binding site in phenylalanine hydroxylase.
abstract: The enzyme phenylalanine hydroxylase (PAH) is defective in the inherited disorder phenylketonuria. PAH, a tetrameric enzyme, is highly regulated and displays positive cooperativity for its substrate, Phe. Whether Phe binds to an allosteric site is a matter of debate, despite several studies worldwide. To address this issue, we generated a dimeric model for Phe-PAH interactions, by performing molecular docking combined with molecular dynamics simulations on human and rat wild-type sequences and also on a human G46S mutant. Our results suggest that the allosteric Phe-binding site lies at the dimeric interface between the regulatory and the catalytic domains of two adjacent subunits. The structural and dynamical features of the site were characterized in depth and described. Interestingly, our findings provide evidence for lower allosteric Phe-binding ability of the G46S mutant than the human wild-type enzyme. This also explains the disease-causing nature of this mutant.
authors.affiliation: a CEINGE-Biotecnologie Avanzate , S.c. a r.l., Napoli , Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Carluccio
authors.affiliation: b Randall Division of Cell and Molecular Biophysics , King's College London , London , UK.
authors.forename: Franca
authors.initials: F
authors.lastname: Fraternali
authors.affiliation: a CEINGE-Biotecnologie Avanzate , S.c. a r.l., Napoli , Italy.|c SDN-Istituto di Ricerca Diagnostica e Nucleare , Napoli , Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Salvatore
authors.affiliation: b Randall Division of Cell and Molecular Biophysics , King's College London , London , UK.
authors.forename: Arianna
authors.initials: A
authors.lastname: Fornili
authors.affiliation: a CEINGE-Biotecnologie Avanzate , S.c. a r.l., Napoli , Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Zagari
mesh_terms: D000494:Allosteric Regulation; D000495:Allosteric Site; D001665:Binding Sites; D020134:Catalytic Domain; D006801:Humans; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009154:Mutation; D010649:Phenylalanine / Q000737:chemistry* / Q000378:metabolism; D010651:Phenylalanine Hydroxylase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D013329:Structure-Activity Relationship
chemical_list: D010649:Phenylalanine; D010651:Phenylalanine Hydroxylase
keywords: allosteric Phe-binding site; hPAH p.G46S mutation; hyperphenylalaninemia; molecular docking simulations; molecular dynamics simulations