title: Structures of the N-acetyltransferase domain of Xylella fastidiosa N-acetyl-L-glutamate synthase/kinase with and without a His tag bound to N-acetyl-L-glutamate.
abstract: Structures of the catalytic N-acetyltransferase (NAT) domain of the bifunctional N-acetyl-L-glutamate synthase/kinase (NAGS/K) from Xylella fastidiosa bound to N-acetyl-L-glutamate (NAG) with and without an N-terminal His tag have been solved and refined at 1.7 and 1.4 Å resolution, respectively. The NAT domain with an N-terminal His tag crystallized in space group P4(1)2(1)2, with unit-cell parameters a=b=51.72, c=242.31 Å. Two subunits form a molecular dimer in the asymmetric unit, which contains ∼41% solvent. The NAT domain without an N-terminal His tag crystallized in space group P21, with unit-cell parameters a=63.48, b=122.34, c=75.88 Å, β=107.6°. Eight subunits, which form four molecular dimers, were identified in the asymmetric unit, which contains ∼38% solvent. The structures with and without the N-terminal His tag provide an opportunity to evaluate how the His tag affects structure and function. Furthermore, multiple subunits in different packing environments allow an assessment of the plasticity of the NAG binding site, which might be relevant to substrate binding and product release. The dimeric structure of the X. fastidiosa N-acetytransferase (xfNAT) domain is very similar to that of human N-acetyltransferase (hNAT), reinforcing the notion that mammalian NAGS is evolutionally derived from bifunctional bacterial NAGS/K.
authors.affiliation: Center for Genetic Medicine Research and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, DC 20010, USA.
authors.forename: Gengxiang
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Southeast Regional Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Department of Cell Biology and Molecular Genetics and Department of Chemistry and Biochemistry, College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, MD 20742, USA.
authors.forename: Norma M
authors.initials: NM
authors.lastname: Allewell
authors.affiliation: Center for Genetic Medicine Research and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, DC 20010, USA.
authors.forename: Mendel
authors.initials: M
authors.lastname: Tuchman
authors.affiliation: Center for Genetic Medicine Research and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, DC 20010, USA.
authors.forename: Dashuang
authors.initials: D
authors.lastname: Shi
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D005970:Glutamate Synthase / Q000737:chemistry; D005971:Glutamates / Q000737:chemistry*; D006639:Histidine; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009842:Oligopeptides; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000737:chemistry*; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D040681:Structural Homology, Protein; D044167:Xylella / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D005971:Glutamates; C471213:His-His-His-His-His-His; D009842:Oligopeptides; D006639:Histidine; D005970:Glutamate Synthase; D017851:Phosphotransferases (Carboxyl Group Acceptor); C018721:acetylglutamate kinase; C016195:N-acetylglutamic acid
keywords: GCN5 N-acetyltransferase; N-acetylglutamate; N-acetylglutamate kinase; N-acetylglutamate synthase; arginine biosynthesis; bifunctional enzymes