title: Electrostatic potential in aminoacylation by aspartyl-tRNAs synthetase.
abstract: Based upon the X-ray structures of complexes between tRNAAsp and aspRS including ATP or Asp-AMP, several electrostatic potentials were calculated by solving the Poisson-Boltzmann equation. The potentials indicate clearly that a Mg2+ ion is essential for binding of ATP and that aspartate is identified electrostatically. The alpha-carboxyl group is forced to contact with the alpha-phosphorus atom of ATP, suggesting its inversion to form an Asp-AMP. When the cognate tRNA is bound to the aspRS:Asp-AMP complex, the 3'-hydroxyl group is located in an electrostatically favorable position to transfer the amino acid as a class II aminoacylation.
authors.affiliation: Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tsunoda
authors.forename: A
authors.initials: A
authors.lastname: Takenaka
authors.forename: J
authors.initials: J
authors.lastname: Cavarelli
authors.forename: B
authors.initials: B
authors.lastname: Rees
authors.forename: J C
authors.initials: JC
authors.lastname: Thierry
authors.forename: D
authors.initials: D
authors.lastname: Moras
mesh_terms: D000215:Acylation; D000255:Adenosine Triphosphate / Q000378:metabolism; D001226:Aspartate-tRNA Ligase / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D008956:Models, Chemical; D015394:Molecular Structure; D012349:RNA, Transfer, Asp / Q000737:chemistry / Q000378:metabolism; D055672:Static Electricity
chemical_list: D012349:RNA, Transfer, Asp; D000255:Adenosine Triphosphate; D001226:Aspartate-tRNA Ligase