title: Structure of the Y94F mutant of Escherichia coli thymidylate synthase.
abstract: Tyr94 of Escherichia coli thymidylate synthase is thought to be involved, either directly or by activation of a water molecule, in the abstraction of a proton from C5 of the 2'-deoxyuridine 5'-monophosphate (dUMP) substrate. Mutation of Tyr94 leads to a 400-fold loss in catalytic activity. The structure of the Y94F mutant has been determined in the native state and as a ternary complex with thymidine 5'-monophosphate (dTMP) and 10-propargyl 5,8-dideazafolate (PDDF). There are no structural changes ascribable to the mutation other than loss of a water molecule hydrogen bonded to the tyrosine OH, which is consistent with a catalytic role for the phenolic OH.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Sue A
authors.initials: SA
authors.lastname: Roberts
authors.forename: David C
authors.initials: DC
authors.lastname: Hyatt
authors.forename: Jerry E
authors.initials: JE
authors.lastname: Honts
authors.forename: Liming
authors.initials: L
authors.lastname: Changchien
authors.forename: Gladys F
authors.initials: GF
authors.lastname: Maley
authors.forename: Frank
authors.initials: F
authors.lastname: Maley
authors.forename: William R
authors.initials: WR
authors.lastname: Montfort
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics*; D020134:Catalytic Domain / Q000235:genetics; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics*; D006860:Hydrogen Bonding; D017665:Hydroxyl Radical / Q000737:chemistry; D010649:Phenylalanine / Q000235:genetics; D013940:Thymidylate Synthase / Q000737:chemistry* / Q000235:genetics*; D014443:Tyrosine / Q000235:genetics; D014867:Water
chemical_list: D029968:Escherichia coli Proteins; D014867:Water; D017665:Hydroxyl Radical; D014443:Tyrosine; D010649:Phenylalanine; D013940:Thymidylate Synthase