title: Sequence diversity of NanA manifests in distinct enzyme kinetics and inhibitor susceptibility.
abstract: Streptococcus pneumoniae is the leading pathogen causing bacterial pneumonia and meningitis. Its surface-associated virulence factor neuraminidase A (NanA) promotes the bacterial colonization by removing the terminal sialyl residues from glycoconjugates on eukaryotic cell surface. The predominant role of NanA in the pathogenesis of pneumococci renders it an attractive target for therapeutic intervention. Despite the highly conserved activity of NanA, our alignment of the 11 NanAs revealed the evolutionary diversity of this enzyme. The amino acid substitutions we identified, particularly those in the lectin domain and in the insertion domain next to the catalytic centre triggered our special interest. We synthesised the representative NanAs and the mutagenized derivatives from E. coli for enzyme kinetics study and neuraminidase inhibitor susceptibility test. Via molecular docking we got a deeper insight into the differences between the two major variants of NanA and their influence on the ligand-target interactions. In addition, our molecular dynamics simulations revealed a prominent intrinsic flexibility of the linker between the active site and the insertion domain, which influences the inhibitor binding. Our findings for the first time associated the primary sequence diversity of NanA with the biochemical properties of the enzyme and with the inhibitory efficiency of neuraminidase inhibitors.
authors.affiliation: Jena University Hospital, Department of Virology and Antiviral Therapy, Hans-Knöll-Straße 2, 07745 Jena, Germany.
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Xu
authors.affiliation: University of Innsbruck, Institute for General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: von Grafenstein
authors.affiliation: Jena University Hospital, Department of Virology and Antiviral Therapy, Hans-Knöll-Straße 2, 07745 Jena, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Walther
authors.affiliation: University of Innsbruck, Institute for General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Julian E
authors.initials: JE
authors.lastname: Fuchs
authors.affiliation: University of Innsbruck, Institute for General, Inorganic and Theoretical Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Klaus R
authors.initials: KR
authors.lastname: Liedl
authors.affiliation: Jena University Hospital, Department of Virology and Antiviral Therapy, Hans-Knöll-Straße 2, 07745 Jena, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Sauerbrei
authors.affiliation: Jena University Hospital, Department of Virology and Antiviral Therapy, Hans-Knöll-Straße 2, 07745 Jena, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Schmidtke
mesh_terms: D019943:Amino Acid Substitution; D004791:Enzyme Inhibitors / Q000378:metabolism*; D014644:Genetic Variation; D007700:Kinetics; D062105:Molecular Docking Simulation; D050505:Mutant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007652:Oxo-Acid-Lyases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013296:Streptococcus pneumoniae / Q000201:enzymology* / Q000235:genetics
chemical_list: D004791:Enzyme Inhibitors; D050505:Mutant Proteins; D007652:Oxo-Acid-Lyases; C018728:N-acetylneuraminate lyase