Molecular cloning and analysis of the nuclear gene MRP-L6 coding for a putative mitochondrial ribosomal protein from Saccharomyces cerevisiae.
The Saccharomyces cerevisiae nuclear gene MRP-L6 was cloned by complementation of the respiratory-deficient mutant pet-ts 2523 with a library of wild-type yeast genomic DNA. The isolated gene was part of a 3.8-kb sequenced DNA fragment containing, in addition to MRP-L6, two unassigned reading frames, ORF1 and ORF2. MRP-L6 codes for a basic protein of 205 amino acids and a molecular mass of 22.8 kDa. The protein exhibits significant sequence similarity to the ribosomal protein L6 of bacteria and chloroplasts. Unlike the corresponding bacterial proteins, however, the MRP-L6 protein (MRP-L6p) contains at its N-terminus a 16 amino-acid leader sequence exhibiting the known characteristics of mitochondrial import signals. Disruption of MRP-L6 leads to the phenotype of a mitochondrial translation-defective, rho-negative yeast mutant. The results are consistent with MRP-L6p representing an essential component of yeast mitochondrial ribosomes. Expression of MRP-L6 was examined, under conditions of glucose repression and derepression, in wild-type cells and in a series of catabolite repression-defective yeast mutants. In most cases, a distinct though small influence of the carbon source on the expression of an MRP-L6/lacZ reported construct was observed.
Harrer
R
R
Lehrstuhl für Biochemie der Universität Erlangen-Nürnberg, Erlangen, Germany.
Schwank
S
S
Schüller
H J
HJ
Schweizer
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D015966:Gene Expression Regulation, Fungal; D015723:Gene Library; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012269:Ribosomal Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D012269:Ribosomal Proteins; C031249:ribosomal protein L6