Acetyltransferase involved in de novo biosynthesis of UDP-N-acetylglucosamine (UDP-GlcNAc) in roots and is required for maintaining normal root cell shape. UDP-GlcNAc is an essential metabolite that serves as an initial sugar donor for N-glycan synthesis and thus plays an important role in protein and lipid glycosylation. acetyl-CoA + D-glucosamine 6-phosphate = CoA + H(+) + N-acetyl-D-glucosamine 6-phosphate Nucleotide-sugar biosynthesis; UDP-N-acetyl-alpha-D-glucosamine biosynthesis; N-acetyl-alpha-D-glucosamine 1-phosphate from alpha-D-glucosamine 6-phosphate (route I): step 1/2. Homodimer. Highly expressed in the root elongation zone and at lower levels in leaves and grains. Short roots, disruption of microtubules and shrinkage of cells in the root elongation zone. Belongs to the acetyltransferase family. GNA1 subfamily.