Adenylosuccinate is an intermediate in the intercoversion of purine

Purine

A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....

 nucleotide

Nucleotide

Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...

s inosine monophosphate (IMP) and adenosine monophosphate

Adenosine monophosphate

Adenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...

 (AMP). The enzyme adenylosuccinate synthase

Adenylosuccinate synthase

In molecular biology, Adenylosuccinate synthase is an enzyme that plays an important role in purine biosynthesis, by catalysing the guanosine triphosphate -dependent conversion of inosine monophosphate and aspartic acid to guanosine diphosphate , phosphate and N--AMP...

 carries out the reaction by the addition of aspartate to IMP and requires the input of energy from a phosphoanhydride bond in the form of guanosine triphosphate

Guanosine triphosphate

Guanosine-5'-triphosphate is a purine nucleoside triphosphate. It can act as a substrate for the synthesis of RNA during the transcription process...

 (GTP). GTP is used instead of adenosine triphosphate

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

(ATP), so the reaction is not dependent on its products.