Structure of the complex of Neisseria gonorrhoeae N-acetyl-L-glutamate synthase with a bound bisubstrate analog

Biochem Biophys Res Commun. 2013 Jan 25;430(4):1253-8. doi: 10.1016/j.bbrc.2012.12.064. Epub 2012 Dec 20.


N-Acetyl-L-glutamate synthase catalyzes the conversion of AcCoA and glutamate to CoA and N-acetyl-L-glutamate (NAG), the first step of the arginine biosynthetic pathway in lower organisms. In mammals, NAG is an obligate cofactor of carbamoyl phosphate synthetase I in the urea cycle. We have previously reported the structures of NAGS from Neisseria gonorrhoeae (ngNAGS) with various substrates bound. Here we reported the preparation of the bisubstrate analog, CoA-S-acetyl-L-glutamate, the crystal structure of ngNAGS with CoA-NAG bound, and kinetic studies of several active site mutants. The results are consistent with a one-step nucleophilic addition-elimination mechanism with Glu353 as the catalytic base and Ser392 as the catalytic acid. The structure of the ngNAGS-bisubstrate complex together with the previous ngNAGS structures delineates the catalytic reaction path for ngNAGS.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acyl Coenzyme A / chemistry*
  • Amino-Acid N-Acetyltransferase / chemistry*
  • Amino-Acid N-Acetyltransferase / genetics
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Catalysis
  • Catalytic Domain
  • Crystallography, X-Ray
  • Glutamates / chemistry*
  • Neisseria gonorrhoeae / enzymology*
  • Protein Structure, Secondary
  • Substrate Specificity


  • Acyl Coenzyme A
  • Bacterial Proteins
  • Glutamates
  • Amino-Acid N-Acetyltransferase