- The GLY1 gene of Saccharomyces cerevisiae encodes a low-specific L-threonine aldolase that catalyzes cleavage of L-allo-threonine and L-threonine to glycine--expression of the gene in Escherichia coli and purification and characterization of the enzyme. Liu, J.Q., Nagata, S., Dairi, T., Misono, H., Shimizu, S., Yamada, H. Eur. J. Biochem. (1997)