Fig. 1
From: Design and characterization of allantoin-inducible expression systems in budding yeast
Schematic diagram of metabolic and regulatory pathways of allantoin metabolism in budding yeast. S. cerevisiae possesses a series of DAL genes for allantoin utilization, which are repressed under normal nitrogen source. Among the DAL-encoded enzymes, there are six proteins primarily involved in allantoin utilization, namely DAL1 (allantoinase), DAL2 (allantoicase), DAL3 (ureidoglycolate hydrolase), DAL4 (allantoin permease), DAL7 (an isoform of malate synthase), and DUR1,2 (urea amidolyase). Additionally, DAL81 and DAL82 function as transcriptional activators of the DAL genes, whereas DAL80 and GZF3 act as inhibitors of their transcription. The green arrows indicate activation, and the red dashed arrows represent inhibition