Purification and biochemical properties of an N-hydroxyarylamine O-acetyltransferase from Escherichia coli.
The N-hydroxyarylamine O-acetyltransferase of Escherichia coli has been expressed as a histidine tagged fusion protein and purified using immobilized nickel column chromatography. The molecular mass of the histidine tagged N-hydroxyarylamine O-acetyltransferase was estimated to be 60.0 kDa by gel filtration and 34.0 kDa by SDS-PAGE and DNA sequence, suggesting that the native enzyme exists as homo dimer. The catalytic properties were investigated using o-aminobenzoic acid as a substrate. No difference in acetyltransfer activity was observed between histidine tagged protein and untagged enzyme. Kinetic studies indicated a ping-pong bi bi mechanism of the catalysis. Inhibition by N-ethylmaleimide and salicylic acid was competitive with o-aminobenzoic acid and non-competitive with acetyl-CoA.
Yamamura
E
E
Molecular Biology Group, Faculty of Engineering, Toyama University, 3190 Gofuku, Toyama, Japan.
Sayama
M
M
Kakikawa
M
M
Mori
M
M
Taketo
A
A
Kodaira
K
K
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000123:Acetyltransferases; D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D010957:Plasmids; D062367:ortho-Aminobenzoates / Q000378:metabolism
D004791:Enzyme Inhibitors; D062367:ortho-Aminobenzoates; D000105:Acetyl Coenzyme A; D000217:Acyltransferases; D000123:Acetyltransferases; C019736:N-hydroxyarylamine O-acetyltransferase