Structure of the complex of Neisseria gonorrhoeae N-acetyl-l-glutamate synthase with a bound bisubstrate analog.Zhao, G., Allewell, N.M., Tuchman, M., Shi, D.
(2013) Biochem Biophys Res Commun 430: 1253-1258
- PubMed: 23261468
- DOI: https://doi.org/10.1016/j.bbrc.2012.12.064
- Primary Citation of Related Structures:
- PubMed Abstract:
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.
Center for Genetic Medicine Research and Department of Integrative Systems Biology, Children's National Medical Center, The George Washington University, Washington, DC 20010, USA.