Structural consequences of a one atom mutation on aspartate transcarbamylase from E. coli.
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.
Cherfils
J
J
Laboratoire de Biologie Physicochimique, Université Paris-Sud, Orsay, France.
Sweet
R M
RM
Middleton
S A
SA
Kantrowitz
E R
ER
Tauc
P
P
Vachette
P
P
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
D012996:Solutions; D014443:Tyrosine; D010649:Phenylalanine; D001221:Aspartate Carbamoyltransferase