title: Structural consequences of a one atom mutation on aspartate transcarbamylase from E. coli.
abstract: Tyr-240 of the catalytic chain of aspartate transcarbamylase from E. coli has been substituted by Phe using site-directed mutagenesis. The regulatory mechanisms of the mutant enzyme have been shown to be slightly less effective than the wild-type enzyme. A study of the structural consequences of the mutation using solution X-ray scattering and computer simulations is reported here. No significant change from the wild-type enzyme is detectable in the quaternary structure. Simulations suggest that the only effect of the mutation is an increased mobility of the mutated side chain.
authors.affiliation: Laboratoire de Biologie Physicochimique, Université Paris-Sud, Orsay, France.
authors.forename: J
authors.initials: J
authors.lastname: Cherfils
authors.forename: R M
authors.initials: RM
authors.lastname: Sweet
authors.forename: S A
authors.initials: SA
authors.lastname: Middleton
authors.forename: E R
authors.initials: ER
authors.lastname: Kantrowitz
authors.forename: P
authors.initials: P
authors.lastname: Tauc
authors.forename: P
authors.initials: P
authors.lastname: Vachette
mesh_terms: D000494:Allosteric Regulation; D001221:Aspartate Carbamoyltransferase / Q000235:genetics / Q000378:metabolism*; D003198:Computer Simulation; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015394:Molecular Structure; D010649:Phenylalanine; D012542:Scattering, Radiation; D012996:Solutions; D013329:Structure-Activity Relationship; D014443:Tyrosine; D014965:X-Rays
chemical_list: D012996:Solutions; D014443:Tyrosine; D010649:Phenylalanine; D001221:Aspartate Carbamoyltransferase