A 40 kd protein binds specifically to the 5'-untranslated regions of yeast mitochondrial mRNAs.
Using a gel mobility shift assay we show that a 40 kd protein (p40), present in extracts of yeast mitochondria, binds specifically to the 5'-untranslated leader of cytochrome c oxidase subunit II mRNA. Binding of p40 to coxII RNA protects an 8-10 nucleotide segment from diethylpyocarbonate modification, indicating that the protein interacts with only a restricted region of the 5'-leader. This segment is located at position -12 with respect to the initiation AUG. Deletion of 10 nucleotides encompassing this site completely abolishes protein binding. Nevertheless, Bal31 deletion analysis within the coxII leader shows that a major part of the leader is essential for p40 binding, suggesting that binding of the protein is also dependent on secondary structural features. p40 binds to other mitochondrial leader mRNAs including those for coxI, coxIII and cyt b. p40 is present in a cytoplasmic (rho0) petite mutant lacking mitochondrial protein synthesis. It is therefore presumably nuclear encoded. The possible biological function of the protein is discussed.
Department of Molecular Cell Biology, University of Amsterdam, The Netherlands.
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B
Papadopoulou
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P
Dekker
J
J
Blom
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LA
Grivell
D001483:Base Sequence; D003576:Electron Transport Complex IV / Q000235:genetics; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D046911:Macromolecular Substances; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals / Q000235:genetics; D012313:RNA / Q000235:genetics* / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D000077278:RNA, Mitochondrial; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism
D005656:Fungal Proteins; D046911:Macromolecular Substances; D021382:Protein Sorting Signals; D012331:RNA, Fungal; D012333:RNA, Messenger; D000077278:RNA, Mitochondrial; D012313:RNA; D003576:Electron Transport Complex IV