Characterization of pco-1 , a newly identified gene which regulates purine catabolism in Neurospora

摘要: A new gene of Neurospora crassa, designated pco-1, was characterized and shown to regulate the expression several genes which encode enzymes required for catabolism purines. Unlike wild type, a pco-1 mutant created by repeat-induced point mutation cannot utilize purines as nitrogen source. The PCO1 protein contains Zn(II)2Cys6 binuclear cluster motif near its N-terminus, followed putative coiled-coil motif. chemical crosslinking experiment demonstrated that forms homodimers. binds CGG-N6-CCG elements located in upstream promoter region four encoding purine catabolic enzymes. Northern blot analysis functional is induction xdh, encodes xanthine dehydrogenase. Moreover, three different Two glutamine-rich domains occur C-terminal at least one regions function, suggesting they might play role transcriptional activation. does not interact with global-acting NIT2 or negative-acting NMR functions catabolite repression. Induction xdh synthesis dehydrogenase completely dependent upon PCO1, but require protein, it controlled novel regulatory mechanism.