Mechanistic issues in asparagine synthetase catalysis.
The enzymatic synthesis of asparagine is an ATP-dependent process that utilizes the nitrogen atom derived from either glutamine or ammonia. Despite a long history of kinetic and mechanistic investigation, there is no universally accepted catalytic mechanism for this seemingly straightforward carboxyl group activating enzyme, especially as regards those steps immediately preceding amide bond formation. This chapter considers four issues dealing with the mechanism: (a) the structural organization of the active site(s) partaking in glutamine utilization and aspartate activation; (b) the relationship of asparagine synthetase to other amidotransferases; (c) the way in which ATP is used to activate the beta-carboxyl group; and (d) the detailed mechanism by which nitrogen is transferred.
Richards
N G
NG
Department of Chemistry, University of Florida, Gainesville 32611, USA.
Schuster
S M
SM
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000641:Ammonia / Q000378:metabolism; D001217:Aspartate-Ammonia Ligase / Q000037:antagonists & inhibitors / Q000145:classification / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D001665:Binding Sites; D005057:Eukaryotic Cells / Q000201:enzymology; D005973:Glutamine / Q000378:metabolism; D008969:Molecular Sequence Data; D011387:Prokaryotic Cells / Q000201:enzymology; D017386:Sequence Homology, Amino Acid
D005973:Glutamine; D001224:Aspartic Acid; D000641:Ammonia; D000255:Adenosine Triphosphate; D001217:Aspartate-Ammonia Ligase