Ribosomal protein L30 is dispensable in the yeast Saccharomyces cerevisiae.

AUTOR(ES)

Baronas-Lowell, D M

RESUMO

In the yeast Saccharomyces cerevisiae, L30 is one of many ribosomal proteins that is encoded by two functional genes. We have cloned and sequenced RPL30B, which shows strong homology to RPL30A. Use of mRNA as a template for a polymerase chain reaction demonstrated that RPL30B contains an intron in its 5' untranslated region. This intron has an unusual 5' splice site, C/GUAUGU. The genomic copies of RPL30A and RPL30B were disrupted by homologous recombination. Growth rates, primer extension, and two-dimensional ribosomal protein analyses of these disruption mutants suggested that RPL30A is responsible for the majority of L30 production. Surprisingly, meiosis of a diploid strain carrying one disrupted RPL30A and one disrupted RPL30B yielded four viable spores. Ribosomes from haploid cells carrying both disrupted genes had no detectable L30, yet such cells grew with a doubling time only 30% longer than that of wild-type cells. Furthermore, depletion of L30 did not alter the ratio of 60S to 40S ribosomal subunits, suggesting that there is no serious effect on the assembly of 60S subunits. Polysome profiles, however, suggest that the absence of L30 leads to the formation of stalled translation initiation complexes.

Documentos Relacionados

• The ABF1 factor is the transcriptional activator of the L2 ribosomal protein genes in Saccharomyces cerevisiae.
• Nucleotide sequence of the tcml gene (ribosomal protein L3) of Saccharomyces cerevisiae.
• Ribosomal protein L3 is involved in replication or maintenance of the killer double-stranded RNA genome of Saccharomyces cerevisiae.
• Tandemly arranged variant 5S ribosomal RNA genes in the yeast Saccharomyces cerevisiae.
• Characterization of the expressed gene and several processed pseudogenes for the mouse ribosomal protein L30 gene family.