N-terminal deletions of a mitochondrial signal sequence in yeast. Targeting information of delta-aminolevulinate synthase is encoded in non-overlapping regions.
A series of N-terminal deletions of the mitochondrial targeting sequence of the HEM1 product, delta-aminolevulinate synthase, was constructed. Targeting ability of mutant signals was assayed in vivo by fusion to beta-galactosidase or to the mature delta-aminolevulinate synthase. In the former case, the subcellular location of the fusion proteins provided a measure of import efficiency. In the later case, constructs were tested for complementation of delta hem 1 strains. We found this complementation assay to be particularly sensitive if the delta hem 1 strain is rho-. The results of these experiments, together with experiments deleting the signal from the carboxyl end, indicate that the targeting information is encoded in non-overlapping regions of the HEM1 signal.
Haldi
M
M
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Guarente
L
L
D000624:5-Aminolevulinate Synthetase / Q000235:genetics*; D000595:Amino Acid Sequence; D015153:Blotting, Western; D003062:Codon; D004271:DNA, Fungal / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D008928:Mitochondria / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000235:genetics; D021382:Protein Sorting Signals / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic; D001616:beta-Galactosidase / Q000235:genetics
D003062:Codon; D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D000624:5-Aminolevulinate Synthetase; D001616:beta-Galactosidase