title: Mitochondrial ATP synthase subunit 9 is not required for viability of the petite-negative yeast Kluyveromyces lactis.
abstract: Specific mutations in nuclear MGI genes encoding the alpha, beta and gamma subunits of the mitochondrial inner membrane F1-ATPase complex allow mitochondrial DNA (mtDNA) to be lost from K. lactis. In the absence of a mutation in any of these three nuclear genes, loss of mtDNA is lethal. These results imply that mtDNA encodes a gene that is essential. Likely candidates for such an essential role are the ATP6, 8 and 9 genes coding for proteins of the ATP synthase-F0 component. The present study removes ATP9 from contention as a vital mitochondrial gene because in a respiratory deficient mutant, Gly- 3. 9, lacking a nuclear mgi mutation, we have found that a rearrangement in mtDNA has deleted 22 amino acids from the carboxy terminus of the 75 amino-acid subunit-9 protein. Rearrangement in mtDNA has occurred by recombination at a 23-bp repeated sequence in the introns of the ATP9 and large ribosomal RNA (LSU) subunit genes. These two introns, of 394 (ATP9) and 410 (LSU) nucleotides, both belong to group 1.
authors.affiliation: Molecular and Population Genetics Group, Research School of Biological Sciences, The Australian National University, GPO Box 475, Canberra City, ACT 2601, Australia.
authors.forename: G D
authors.initials: GD
authors.lastname: Clark-Walker
authors.forename: F
authors.initials: F
authors.lastname: Francois
authors.forename: X J
authors.initials: XJ
authors.lastname: Chen
authors.forename: M R
authors.initials: MR
authors.lastname: Vieira Da Silva
authors.forename: M L
authors.initials: ML
authors.lastname: Claisse
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis; D017353:Gene Deletion; D015321:Gene Rearrangement; D007438:Introns; D007716:Kluyveromyces / Q000201:enzymology* / Q000235:genetics; D025261:Mitochondrial Proton-Translocating ATPases; D008969:Molecular Sequence Data; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000235:genetics*; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D017421:Sequence Analysis
chemical_list: D004272:DNA, Mitochondrial; D005656:Fungal Proteins; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases