The biosynthesis of asparagine originates with aspartate using a transaminase enzyme.  The enzyme asparagine synthetase produces asparagine, AMP, glutamate, and pyrophosphate from aspartate, glutamine, and ATP.  In the asparagine synthetase reaction, ATP is used to activate aspartate, forming β-aspartyl-AMP.  Glutamine donates an ammonium group, which reacts with β-aspartyl-AMP to form asparagine and free AMP.
Two asparagine synthetases are found in bacteria. Both are referred to as the AsnC protein. They are coded for by the genes AsnA and AsnB. AsnC is autogenously regulated, which is where the product of a structural gene regulates the expression of the operon in which the genes reside. The stimulating effect of AsnC on AsnA transcription is downregulated by asparagine. However, the autoregulation of AsnC is not affected by asparagine.