J. Biol. Chem., Vol. 265, Issue 16, 9011-9014, 06, 1990
Cloning of a cDNA encoding adenylosuccinate lyase by functional complementation in Escherichia coli
J Aimi, J Badylak, J Williams, ZD Chen, H Zalkin and JE Dixon
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
Adenylosuccinate lyase was cloned by functional complementation of an
Escherichia coli purB mutant using an avian liver cDNA expression library.
The derived amino acid sequence is homologous to the bacterial purB-encoded
adenylosuccinate lyase which catalyzes the same two steps in purine
biosynthesis as the enzyme from animals. Avian adenylosuccinate lyase also
shows regions of extensive sequence similarity to the urea cycle enzyme,
argininosuccinate lyase. This homology suggests a similar mechanism for
catalysis. Homology of adenylosuccinate and argininosuccinate lyases is
intriguing because chickens do not utilize the urea cycle in nitrogen
excretion. This is the first report of the cloning of a eukaryotic cDNA
encoding adenylosuccinate lyase, and it affords a route to isolate the
corresponding human gene which has been suggested to be defective in
autistic children.