YCL064C is a gene in the genome of Saccharomyces cerevisiae, the most common species of yeast. Its function is the catalyzation of the degradation of both L-serine and L-threonine. In order to survive using serine or threonine as the sole nitrogen source, YCL064C must be present and functional. It is transcriptionally induced by the presence of Lserine and Lthreonine.[1][2][3] The gene is 360 amino acids in length,[4] and is also known under the synonym of CHA1.[5]