Structure of acetylglutamate kinase, a key enzyme for arginine biosynthesis and a prototype for the amino acid kinase enzyme family, during catalysis

Structure. 2002 Mar;10(3):329-42. doi: 10.1016/s0969-2126(02)00721-9.


N-Acetyl-L-glutamate kinase (NAGK), a member of the amino acid kinase family, catalyzes the second and frequently controlling step of arginine synthesis. The Escherichia coli NAGK crystal structure to 1.5 A resolution reveals a 258-residue subunit homodimer nucleated by a central 16-stranded molecular open beta sheet sandwiched between alpha helices. In each subunit, AMPPNP, as an alphabetagamma-phosphate-Mg2+ complex, binds along the sheet C edge, and N-acetyl-L-glutamate binds near the dyadic axis with its gamma-COO- aligned at short distance from the gamma-phosphoryl, indicating associative phosphoryl transfer assisted by: (1) Mg2+ complexation; (2) the positive charges on Lys8, Lys217, and on two helix dipoles; and (3) by hydrogen bonding with the y-phosphate. The structural resemblance with carbamate kinase and the alignment of the sequences suggest that NAGK is a structural and functional prototype for the amino acid kinase family, which differs from other acylphosphate-making devices represented by phosphoglycerate kinase, acetate kinase, and biotin carboxylase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arginine / biosynthesis*
  • Binding Sites
  • Catalysis
  • Crystallography, X-Ray
  • Dimerization
  • Escherichia coli / enzymology
  • Molecular Sequence Data
  • Molecular Structure
  • Multigene Family
  • Phosphotransferases (Carboxyl Group Acceptor) / chemistry*
  • Phosphotransferases (Carboxyl Group Acceptor) / genetics
  • Phosphotransferases (Carboxyl Group Acceptor) / metabolism
  • Protein Structure, Secondary*
  • Protein Structure, Tertiary*
  • Sequence Alignment


  • Arginine
  • Phosphotransferases (Carboxyl Group Acceptor)
  • acetylglutamate kinase

Associated data

  • PDB/1GS5
  • PDB/1GSJ