The helicase CaHmi1p is required for wild-type mitochondrial DNA organization in Candida albicans.

摘要: The mechanistic details of mtDNA maintenance in petite-negative yeasts have remained largely unexplored. We report here that the DNA helicase Hmi1p plays a crucial role stability Candida albicans . Like its counterpart Saccharomyces cerevisiae , C. (CaHmi1p) contains C-terminal mitochondrial targeting signal is functional both organisms. Biochemical analysis demonstrates CaHmi1p protein possessing ATP-dependent 3′–5′ DNA-unwinding activity. Deletion HMI1 alleles does not lead to complete loss ; however, substantial fragmentation wild-type genome, reduction mass and nucleoid distribution occur. Specific regions genome give rise molecule populations with altered characteristics upon CaHMI1 deletion. Fragmentation can be reversed by reintroduction CaHmi1p. This first time gene required for S. has been demonstrated nonessential yeast.