Acceptor substrate binding revealed by crystal structure of human glucosamine-6-phosphate N-acetyltransferase 1.
Glucosamine-6-phosphate (GlcN6P) N-acetyltransferase 1 (GNA1) is a key enzyme in the pathway toward biosynthesis of UDP-N-acetylglucosamine, an important donor substrate for N-linked glycosylation. GNA1 catalyzes the formation of N-acetylglucosamine-6-phosphate (GlcNAc6P) from acetyl-CoA (AcCoA) and the acceptor substrate GlcN6P. Here, we report crystal structures of human GNA1, including apo GNA1, the GNA1-GlcN6P complex and an E156A mutant. Our work showed that GlcN6P binds to GNA1 without the help of AcCoA binding. Structural analyses and mutagenesis studies have shed lights on the charge distribution in the GlcN6P binding pocket, and an important role for Glu156 in the substrate binding. Hence, these findings have broadened our knowledge of structural features required for the substrate affinity of GNA1.
Wang
Juan
J
National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
Liu
Xiang
X
Liang
Yu-He
YH
Li
Lan-Fen
LF
Su
Xiao-Dong
XD
D000105:Acetyl Coenzyme A / Q000737:chemistry; D000409:Alanine / Q000737:chemistry / Q000235:genetics; D001051:Apoenzymes / Q000737:chemistry; D018360:Crystallography, X-Ray; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000737:chemistry; D051081:Glucosamine 6-Phosphate N-Acetyltransferase / Q000737:chemistry* / Q000235:genetics; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives* / Q000737:chemistry; D018698:Glutamic Acid / Q000737:chemistry / Q000235:genetics; D006801:Humans; D016296:Mutagenesis
D001051:Apoenzymes; C001293:glucosamine 6-phosphate; D018698:Glutamic Acid; D019298:Glucose-6-Phosphate; D000105:Acetyl Coenzyme A; C494970:GNPNAT1 protein, human; D051081:Glucosamine 6-Phosphate N-Acetyltransferase; D005944:Glucosamine; D000409:Alanine