An alternative, arginase-independent pathway for arginine metabolism in Kluyveromyces lactis involves guanidinobutyrase as a key enzyme.

ABSTRACT: Most available knowledge on fungal arginine metabolism is derived from studies on Saccharomyces cerevisiae, in which arginine catabolism is initiated by releasing urea via the arginase reaction. Orthologues of the S. cerevisiae genes encoding the first three enzymes in the arginase pathway were cloned from Kluyveromyces lactis and shown to functionally complement the corresponding deletion in S. cerevisiae. Surprisingly, deletion of the single K. lactis arginase gene KlCAR1 did not completely abolish growth on arginine as nitrogen source. Growth rate of the deletion mutant strongly increased during serial transfer in shake-flask cultures. A combination of RNAseq-based transcriptome analysis and (13)C-(15)N-based flux analysis was used to elucidate the arginase-independent pathway. Isotopic

SUBMITTER: Romagnoli G 

PROVIDER: S-EPMC4149782 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature