A novel mitochondrial DEAD box protein (Mrh4) required for maintenance of mtDNA in Saccharomyces cerevisiae.
In a screen of nuclear genes that assist splicing of mitochondrial localized group II introns in yeast we isolated low-copy number suppressors of splicing and respiratory-deficient point mutants of intron aI5gamma, the last intron of the gene encoding cytochrome c oxidase subunit I. One of the genes found contains the open reading frame (ORF) YGL064c that has previously been proposed to encode a putative RNA helicase of the DEAD box family. Deletion of the ORF gives rise to 100% cytoplasmic petites, indicating that the protein plays an essential role in the mitochondrial RNA metabolism. Overexpression of YGL064c-GFP fusions clearly revealed a mitochondrial localization of the protein. The gene encodes the fourth putative RNA helicase of Saccharomyces cerevisiae implicated in a mitochondrial function and was therefore termed MRH4 (for mitochondrial RNA helicase).
Schmidt
Udo
U
Department of Microbiology and Genetics, Faculty III, University of Technology Berlin, Gustav-Meyer-Allee 25, Germany. u.schmidt@lb.tu-berlin.de
Lehmann
Karola
K
Stahl
Ulf
U
D000595:Amino Acid Sequence; D053487:DEAD-box RNA Helicases; D004272:DNA, Mitochondrial / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D007438:Introns; D008969:Molecular Sequence Data; D009154:Mutation; D012313:RNA; D020365:RNA Helicases / Q000235:genetics* / Q000378:metabolism*; D012326:RNA Splicing; D000077278:RNA, Mitochondrial; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D004272:DNA, Mitochondrial; D000077278:RNA, Mitochondrial; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; C478542:MRH4 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases