Abstrakt: |
The purine catabolic enzymes uricase, allantoinase, allantoicase and ureidoglycollase are highly induced by purines in wild-type Schizosaccharomyces pombe cells. In contrast, urease activity is constitutive. Attempts have been made to identify the inducer or inducers involved. There appears to be a sequential form of induction, uricase being induced by uric acid, allantoinase by allantoic acid (and possibly allantoin), allantoicase by allantoic acid, ureidoglycollase by ureidoglycollic acid. This sequential control of purine breakdown is compared with that found in other fungi. [ABSTRACT FROM AUTHOR] |